Q:

OpenVPN disables WiFi adapter afer connecting; connects after re-enabling it but no VPN hosts connectivity

I want to connect from my Windows 7 Enterprise PC to OpenVPN server.  I have OpenVPN client version 2.1.1 installed. 
I have currently two problems:
1) After I start OpenVPN GUI and connect the connection process goes just fine.  But immediately after I get "Initialization Sequence Completed" my Wifi network adapter suddenly appears to be disabled O_O Naturally, this breaks all Internet connectivity including VPN tunnel, so in log it looks like:
...
Sat Mar 09 11:28:18 2013 Initialization Sequence Completed
Sat Mar 09 11:28:25 2013 Connection reset, restarting [0]
Sat Mar 09 11:28:25 2013 TCP/UDP: Closing socket
Sat Mar 09 11:28:25 2013 SIGUSR1[soft,connection-reset] received, process restarting
Sat Mar 09 11:28:25 2013 Restart pause, 5 second(s)
...

If I manually enable Wireless network adapter through Network connections control panel, OpenVPN connects OK second time (at least, it says that "Initialization Sequence Completed" and icon in tray turns green) but here another problem appears:
2) After I successfully connect for the second time, I get zero connectivity to all VPN hosts.  I suspect that this involves routing somehow as when I try to tracert a host that is behind VPN, the trace goes through primary WiFi router, which is definitely wrong. 
Last but not least, the problem is hot steadily reproducible.  The first problem happens always, but the second one happens only in ~70% cases, meaning that sometimes I can connect and work just fine from the second attempt. 
I have another laptop - also Windows 7, lives in the same WiFi network, same OpenVPN version - which connects perfectly fine (?!). 
Has anyone got the similar behavior?  Any clues? 
UPD
Tried solution with deleting network adapters from OpenVPN: Windows 7 x64 client cannot see remote LAN, but XP client can.  Worked once after deleting all Microsoft ISATAP xxx adapters, but only lasted up to reboot.  Second time did not work, so I think it was a pure coincidence with something else. 
UPD2: detailed logs
When I just rebooted my PC, routing table looks like that:
===========================================================================
Interface List
 17...00 ff ca 1c 39 86 ......TAP-Win32 Adapter V9
 13...20 16 d8 91 32 c4 ......Bluetooth Device (Personal Area Network)
 12...84 3a 4b 12 44 f8 ......Intel(R) Centrino(R) Advanced-N 6205
 11...e0 db 55 e9 c0 17 ......Intel(R) 82579LM Gigabit Network Connection
  1...........................Software Loopback Interface 1
 18...00 00 00 00 00 00 00 e0 Microsoft ISATAP Adapter
 19...00 00 00 00 00 00 00 e0 Microsoft ISATAP Adapter #2
 16...00 00 00 00 00 00 00 e0 Teredo Tunneling Pseudo-Interface
===========================================================================

IPv4 Route Table
===========================================================================
Active Routes:
Network Destination        Netmask          Gateway       Interface  Metric
          0.0.0.0          0.0.0.0      192.168.1.1     192.168.1.11     25
        127.0.0.0        255.0.0.0         On-link         127.0.0.1    306
        127.0.0.1  255.255.255.255         On-link         127.0.0.1    306
  127.255.255.255  255.255.255.255         On-link         127.0.0.1    306
      192.168.1.0    255.255.255.0         On-link      192.168.1.11    281
     192.168.1.11  255.255.255.255         On-link      192.168.1.11    281
    192.168.1.255  255.255.255.255         On-link      192.168.1.11    281
        224.0.0.0        240.0.0.0         On-link         127.0.0.1    306
        224.0.0.0        240.0.0.0         On-link      192.168.1.11    281
  255.255.255.255  255.255.255.255         On-link         127.0.0.1    306
  255.255.255.255  255.255.255.255         On-link      192.168.1.11    281
===========================================================================
Persistent Routes:
  None

192.168.1.1 is my WiFi router.  Then I start OpenVPN GUI with Administrator privileges and get the following:
Tue Mar 12 22:01:16 2013 OpenVPN 2.2.2 Win32-MSVC++ [SSL] [LZO2] [PKCS11] built on Dec 15 2011
Tue Mar 12 22:01:16 2013 WARNING: No server certificate verification method has been enabled.   See http://openvpn.net/howto.html#mitm for more info. 
Tue Mar 12 22:01:16 2013 NOTE: OpenVPN 2.1 requires '--script-security 2' or higher to call user-defined scripts or executables
Tue Mar 12 22:01:16 2013 LZO compression initialized
Tue Mar 12 22:01:16 2013 Control Channel MTU parms [ L:1544 D:140 EF:40 EB:0 ET:0 EL:0 ]
Tue Mar 12 22:01:16 2013 Socket Buffers: R=[8192->8192] S=[8192->8192]
Tue Mar 12 22:01:16 2013 Data Channel MTU parms [ L:1544 D:1450 EF:44 EB:135 ET:0 EL:0 AF:3/1 ]
Tue Mar 12 22:01:16 2013 Local Options hash (VER=V4): '69109d17'
Tue Mar 12 22:01:16 2013 Expected Remote Options hash (VER=V4): 'c0103fa8'
Tue Mar 12 22:01:16 2013 Attempting to establish TCP connection with <server address and port>
Tue Mar 12 22:01:17 2013 TCP connection established with <server address and port>
Tue Mar 12 22:01:17 2013 TCPv4_CLIENT link local: [undef]
Tue Mar 12 22:01:17 2013 TCPv4_CLIENT link remote: <server address and port>
Tue Mar 12 22:01:17 2013 TLS: Initial packet from <server address and port>, sid=c2fbe2fc 7ac9518f
Tue Mar 12 22:01:19 2013 VERIFY OK: depth=1, <key params>
Tue Mar 12 22:01:19 2013 VERIFY OK: depth=0, <key params>
Tue Mar 12 22:01:23 2013 Data Channel Encrypt: Cipher 'BF-CBC' initialized with 128 bit key
Tue Mar 12 22:01:23 2013 Data Channel Encrypt: Using 160 bit message hash 'SHA1' for HMAC authentication
Tue Mar 12 22:01:23 2013 Data Channel Decrypt: Cipher 'BF-CBC' initialized with 128 bit key
Tue Mar 12 22:01:23 2013 Data Channel Decrypt: Using 160 bit message hash 'SHA1' for HMAC authentication
Tue Mar 12 22:01:23 2013 Control Channel: TLSv1, cipher TLSv1/SSLv3 DHE-RSA-AES256-SHA, 2048 bit RSA
Tue Mar 12 22:01:23 2013 [New_dot_server] Peer Connection Initiated with <server address and port>
Tue Mar 12 22:01:25 2013 SENT CONTROL [New_dot_server]: 'PUSH_REQUEST' (status=1)
Tue Mar 12 22:01:26 2013 PUSH: Received control message: 'PUSH_REPLY,route 172.16.0.0 255.255.255.0,topology net30,ping 10,ping-restart 120,ifconfig 172.16.0.22 172.16.0.21'
Tue Mar 12 22:01:26 2013 OPTIONS IMPORT: timers and/or timeouts modified
Tue Mar 12 22:01:26 2013 OPTIONS IMPORT: --ifconfig/up options modified
Tue Mar 12 22:01:26 2013 OPTIONS IMPORT: route options modified
Tue Mar 12 22:01:26 2013 ROUTE default_gateway=192.168.1.1
Tue Mar 12 22:01:26 2013 TAP-WIN32 device [Local Area Connection 2] opened: \\.\Global\{CA1C3986-D7B0-4F47-80BD-8E8C6F671C1D}.tap
Tue Mar 12 22:01:26 2013 TAP-Win32 Driver Version 9.9 
Tue Mar 12 22:01:26 2013 TAP-Win32 MTU=1500
Tue Mar 12 22:01:26 2013 Notified TAP-Win32 driver to set a DHCP IP/netmask of 172.16.0.22/255.255.255.252 on interface {CA1C3986-D7B0-4F47-80BD-8E8C6F671C1D} [DHCP-serv: 172.16.0.21, lease-time: 31536000]
Tue Mar 12 22:01:26 2013 Successful ARP Flush on interface [17] {CA1C3986-D7B0-4F47-80BD-8E8C6F671C1D}

at this point WiFi connection breaks and WiFi adapter shows as disabled in Control Panel->Network and Sharing Center->Change adapter properties.  In VPN log it's displayed as:
Tue Mar 12 22:01:27 2013 Connection reset, restarting [-1]
Tue Mar 12 22:01:27 2013 TCP/UDP: Closing socket
Tue Mar 12 22:01:27 2013 SIGUSR1[soft,connection-reset] received, process restarting
Tue Mar 12 22:01:27 2013 Restart pause, 5 second(s)
Tue Mar 12 22:01:32 2013 WARNING: No server certificate verification method has been enabled.   See http://openvpn.net/howto.html#mitm for more info. 
Tue Mar 12 22:01:32 2013 NOTE: OpenVPN 2.1 requires '--script-security 2' or higher to call user-defined scripts or executables
Tue Mar 12 22:01:32 2013 Re-using SSL/TLS context
Tue Mar 12 22:01:32 2013 LZO compression initialized
Tue Mar 12 22:01:32 2013 Control Channel MTU parms [ L:1544 D:140 EF:40 EB:0 ET:0 EL:0 ]
Tue Mar 12 22:01:32 2013 Socket Buffers: R=[8192->8192] S=[8192->8192]
Tue Mar 12 22:01:32 2013 RESOLVE: Cannot resolve host address: <server domain name>: [NO_DATA] The requested name is valid but does not have an IP address. 
Tue Mar 12 22:01:32 2013 Data Channel MTU parms [ L:1544 D:1450 EF:44 EB:135 ET:0 EL:0 AF:3/1 ]
Tue Mar 12 22:01:32 2013 Local Options hash (VER=V4): '69109d17'
Tue Mar 12 22:01:32 2013 Expected Remote Options hash (VER=V4): 'c0103fa8'
Tue Mar 12 22:01:32 2013 RESOLVE: Cannot resolve host address: <server domain name>: [NO_DATA] The requested name is valid but does not have an IP address. 
Tue Mar 12 22:01:37 2013 RESOLVE: Cannot resolve host address: <server domain name>: [NO_DATA] The requested name is valid but does not have an IP address. 
Tue Mar 12 22:01:42 2013 RESOLVE: Cannot resolve host address: <server domain name>: [NO_DATA] The requested name is valid but does not have an IP address. 
...

At this point WiFi adapter is down.  Routing table:
IPv4 Route Table
===========================================================================
Active Routes:
Network Destination        Netmask          Gateway       Interface  Metric
        127.0.0.0        255.0.0.0         On-link         127.0.0.1    306
        127.0.0.1  255.255.255.255         On-link         127.0.0.1    306
  127.255.255.255  255.255.255.255         On-link         127.0.0.1    306
      172.16.0.20  255.255.255.252         On-link       172.16.0.22    286
      172.16.0.22  255.255.255.255         On-link       172.16.0.22    286
      172.16.0.23  255.255.255.255         On-link       172.16.0.22    286
        224.0.0.0        240.0.0.0         On-link         127.0.0.1    306
        224.0.0.0        240.0.0.0         On-link       172.16.0.22    286
  255.255.255.255  255.255.255.255         On-link         127.0.0.1    306
  255.255.255.255  255.255.255.255         On-link       172.16.0.22    286
===========================================================================
Persistent Routes:
  None

Then I go to adapter settings and manually enable WiFi adapter.  In VPN log it shows as:
...
Tue Mar 12 22:02:57 2013 RESOLVE: Cannot resolve host address: <server domain name>: [NO_DATA] The requested name is valid but does not have an IP address. 
Tue Mar 12 22:03:02 2013 RESOLVE: Cannot resolve host address: <server domain name>: [NO_DATA] The requested name is valid but does not have an IP address. 
Tue Mar 12 22:03:07 2013 Attempting to establish TCP connection with <server address and port>
Tue Mar 12 22:03:07 2013 TCP connection established with <server address and port>
Tue Mar 12 22:03:07 2013 TCPv4_CLIENT link local: [undef]
Tue Mar 12 22:03:07 2013 TCPv4_CLIENT link remote: <server address and port>
Tue Mar 12 22:03:07 2013 TLS: Initial packet from <server address and port>, sid=217a2257 11069cf8
Tue Mar 12 22:03:10 2013 VERIFY OK: depth=1, <key details>
Tue Mar 12 22:03:10 2013 VERIFY OK: depth=0, <key details>
Tue Mar 12 22:03:14 2013 Data Channel Encrypt: Cipher 'BF-CBC' initialized with 128 bit key
Tue Mar 12 22:03:14 2013 Data Channel Encrypt: Using 160 bit message hash 'SHA1' for HMAC authentication
Tue Mar 12 22:03:14 2013 Data Channel Decrypt: Cipher 'BF-CBC' initialized with 128 bit key
Tue Mar 12 22:03:14 2013 Data Channel Decrypt: Using 160 bit message hash 'SHA1' for HMAC authentication
Tue Mar 12 22:03:14 2013 Control Channel: TLSv1, cipher TLSv1/SSLv3 DHE-RSA-AES256-SHA, 2048 bit RSA
Tue Mar 12 22:03:14 2013 [New_dot_server] Peer Connection Initiated with <server address and port>
Tue Mar 12 22:03:16 2013 SENT CONTROL [New_dot_server]: 'PUSH_REQUEST' (status=1)
Tue Mar 12 22:03:17 2013 PUSH: Received control message: 'PUSH_REPLY,route 172.16.0.0 255.255.255.0,topology net30,ping 10,ping-restart 120,ifconfig 172.16.0.22 172.16.0.21'
Tue Mar 12 22:03:17 2013 OPTIONS IMPORT: timers and/or timeouts modified
Tue Mar 12 22:03:17 2013 OPTIONS IMPORT: --ifconfig/up options modified
Tue Mar 12 22:03:17 2013 OPTIONS IMPORT: route options modified
Tue Mar 12 22:03:17 2013 Preserving previous TUN/TAP instance: Local Area Connection 2
Tue Mar 12 22:03:17 2013 Initialization Sequence Completed

After that OpenVPN GUI icon in tray turns green and a popup with IP address appears.  I have normal Internet connectivity but zero VPN connectivity.  Routing table is
IPv4 Route Table
===========================================================================
Active Routes:
Network Destination        Netmask          Gateway       Interface  Metric
          0.0.0.0          0.0.0.0      192.168.1.1     192.168.1.11     25
        127.0.0.0        255.0.0.0         On-link         127.0.0.1    306
        127.0.0.1  255.255.255.255         On-link         127.0.0.1    306
  127.255.255.255  255.255.255.255         On-link         127.0.0.1    306
      172.16.0.20  255.255.255.252         On-link       172.16.0.22    286
      172.16.0.22  255.255.255.255         On-link       172.16.0.22    286
      172.16.0.23  255.255.255.255         On-link       172.16.0.22    286
      192.168.1.0    255.255.255.0         On-link      192.168.1.11    281
     192.168.1.11  255.255.255.255         On-link      192.168.1.11    281
    192.168.1.255  255.255.255.255         On-link      192.168.1.11    281
        224.0.0.0        240.0.0.0         On-link         127.0.0.1    306
        224.0.0.0        240.0.0.0         On-link       172.16.0.22    286
        224.0.0.0        240.0.0.0         On-link      192.168.1.11    281
  255.255.255.255  255.255.255.255         On-link         127.0.0.1    306
  255.255.255.255  255.255.255.255         On-link       172.16.0.22    286
  255.255.255.255  255.255.255.255         On-link      192.168.1.11    281
===========================================================================
Persistent Routes:
  None

...and here I kill myself bashing my head against the wall. 
UPDATE3
Config files:
Server (Ubuntu Server):
# Which local IP address should OpenVPN
# listen on? ( optional)
;local a.b.c.d

# Which TCP/UDP port should OpenVPN listen on? 
# If you want to run multiple OpenVPN instances
# on the same machine, use a different port
# number for each one.   You will need to
# open up this port on your firewall. 
port 3307

# TCP or UDP server? 
proto tcp
;proto udp

# "dev tun" will create a routed IP tunnel,
# "dev tap" will create an ethernet tunnel. 
# Use "dev tap0" if you are ethernet bridging
# and have precreated a tap0 virtual interface
# and bridged it with your ethernet interface. 
# If you want to control access policies
# over the VPN, you must create firewall
# rules for the the TUN/TAP interface. 
# On non-Windows systems, you can give
# an explicit unit number, such as tun0. 
# On Windows, use "dev-node" for this. 
# On most systems, the VPN will not function
# unless you partially or fully disable
# the firewall for the TUN/TAP interface. 
;dev tap
dev tun

# Windows needs the TAP-Win32 adapter name
# from the Network Connections panel if you
# have more than one.   On XP SP2 or higher,
# you may need to selectively disable the
# Windows firewall for the TAP adapter. 
# Non-Windows systems usually don't need this. 
;dev-node MyTap

# SSL/TLS root certificate (ca), certificate
# (cert), and private key (key).   Each client
# and the server must have their own cert and
# key file.   The server and all clients will
# use the same ca file. 
#
# See the "easy-rsa" directory for a series
# of scripts for generating RSA certificates
# and private keys.   Remember to use
# a unique Common Name for the server
# and each of the client certificates. 
#
# Any X509 key management system can be used. 
# OpenVPN can also use a PKCS #12 formatted key file
# (see "pkcs12" directive in man page). 
ca /etc/openvpn/ca.crt
cert /etc/openvpn/server.crt
key /etc/openvpn/server.key  # This file should be kept secret

# Diffie hellman parameters. 
# Generate your own with:
#   openssl dhparam -out dh1024.pem 1024
# Substitute 2048 for 1024 if you are using
# 2048 bit keys.  
dh /etc/openvpn/dh2048.pem

# Configure server mode and supply a VPN subnet
# for OpenVPN to draw client addresses from. 
# The server will take 10.8.0.1 for itself,
# the rest will be made available to clients. 
# Each client will be able to reach the server
# on 10.8.0.1.  Comment this line out if you are
# ethernet bridging.  See the man page for more info. 
server 172.16.0.0 255.255.255.0

# Maintain a record of client <-> virtual IP address
# associations in this file.   If OpenVPN goes down or
# is restarted, reconnecting clients can be assigned
# the same virtual IP address from the pool that was
# previously assigned. 
ifconfig-pool-persist ipp.txt

# Configure server mode for ethernet bridging. 
# You must first use your OS's bridging capability
# to bridge the TAP interface with the ethernet
# NIC interface.   Then you must manually set the
# IP/netmask on the bridge interface, here we
# assume 10.8.0.4/255.255.255.0.   Finally we
# must set aside an IP range in this subnet
# (start=10.8.0.50 end=10.8.0.100) to allocate
# to connecting clients.   Leave this line commented
# out unless you are ethernet bridging. 
;server-bridge 10.8.0.4 255.255.255.0 10.8.0.50 10.8.0.100

# Push routes to the client to allow it
# to reach other private subnets behind
# the server.   Remember that these
# private subnets will also need
# to know to route the OpenVPN client
# address pool (10.8.0.0/255.255.255.0)
# back to the OpenVPN server. 
;push "route 192.168.10.0 255.255.255.0"
;push "route 192.168.20.0 255.255.255.0"

# To assign specific IP addresses to specific
# clients or if a connecting client has a private
# subnet behind it that should also have VPN access,
# use the subdirectory "ccd" for client-specific
# configuration files (see man page for more info). 

# EXAMPLE: Suppose the client
# having the certificate common name "Thelonious"
# also has a small subnet behind his connecting
# machine, such as 192.168.40.128/255.255.255.248. 
# First, uncomment out these lines:
;client-config-dir ccd
;route 192.168.40.128 255.255.255.248
# Then create a file ccd/Thelonious with this line:
#   iroute 192.168.40.128 255.255.255.248
# This will allow Thelonious' private subnet to
# access the VPN.   This example will only work
# if you are routing, not bridging, i.e. you are
# using "dev tun" and "server" directives. 

# EXAMPLE: Suppose you want to give
# Thelonious a fixed VPN IP address of 10.9.0.1. 
# First uncomment out these lines:
;client-config-dir ccd
;route 10.9.0.0 255.255.255.252
# Then add this line to ccd/Thelonious:
#   ifconfig-push 10.9.0.1 10.9.0.2

# Suppose that you want to enable different
# firewall access policies for different groups
# of clients.   There are two methods:
# (1) Run multiple OpenVPN daemons, one for each
#     group, and firewall the TUN/TAP interface
#     for each group/daemon appropriately. 
# (2) (Advanced) Create a script to dynamically
#     modify the firewall in response to access
#     from different clients.   See man
#     page for more info on learn-address script. 
;learn-address ./script

# If enabled, this directive will configure
# all clients to redirect their default
# network gateway through the VPN, causing
# all IP traffic such as web browsing and
# and DNS lookups to go through the VPN
# (The OpenVPN server machine may need to NAT
# the TUN/TAP interface to the internet in
# order for this to work properly). 
# CAVEAT: May break client's network config if
# client's local DHCP server packets get routed
# through the tunnel.   Solution: make sure
# client's local DHCP server is reachable via
# a more specific route than the default route
# of 0.0.0.0/0.0.0.0. 
;push "redirect-gateway"

# Certain Windows-specific network settings
# can be pushed to clients, such as DNS
# or WINS server addresses.   CAVEAT:
# http://openvpn.net/faq.html#dhcpcaveats
;push "dhcp-option DNS 10.8.0.1"
;push "dhcp-option WINS 10.8.0.1"

# Uncomment this directive to allow different
# clients to be able to "see" each other. 
# By default, clients will only see the server. 
# To force clients to only see the server, you
# will also need to appropriately firewall the
# server's TUN/TAP interface. 
client-to-client

# Uncomment this directive if multiple clients
# might connect with the same certificate/key
# files or common names.   This is recommended
# only for testing purposes.   For production use,
# each client should have its own certificate/key
# pair. 
#
# IF YOU HAVE NOT GENERATED INDIVIDUAL
# CERTIFICATE/KEY PAIRS FOR EACH CLIENT,
# EACH HAVING ITS OWN UNIQUE "COMMON NAME",
# UNCOMMENT THIS LINE OUT. 
;duplicate-cn

# The keepalive directive causes ping-like
# messages to be sent back and forth over
# the link so that each side knows when
# the other side has gone down. 
# Ping every 10 seconds, assume that remote
# peer is down if no ping received during
# a 120 second time period. 
keepalive 10 120

# For extra security beyond that provided
# by SSL/TLS, create an "HMAC firewall"
# to help block DoS attacks and UDP port flooding. 
#
# Generate with:
#   openvpn --genkey --secret ta.key
#
# The server and each client must have
# a copy of this key. 
# The second parameter should be '0'
# on the server and '1' on the clients. 
;tls-auth ta.key 0 # This file is secret

# Select a cryptographic cipher. 
# This config item must be copied to
# the client config file as well. 
;cipher BF-CBC        # Blowfish (default)
;cipher AES-128-CBC   # AES
;cipher DES-EDE3-CBC  # Triple-DES

# Enable compression on the VPN link. 
# If you enable it here, you must also
# enable it in the client config file. 
comp-lzo

# The maximum number of concurrently connected
# clients we want to allow. 
;max-clients 100

# It's a good idea to reduce the OpenVPN
# daemon's privileges after initialization. 
#
# You can uncomment this out on
# non-Windows systems. 
user nobody
group nogroup

# The persist options will try to avoid
# accessing certain resources on restart
# that may no longer be accessible because
# of the privilege downgrade. 
persist-key
persist-tun

# Output a short status file showing
# current connections, truncated
# and rewritten every minute. 
status openvpn-status.log

# By default, log messages will go to the syslog (or
# on Windows, if running as a service, they will go to
# the "\Program Files\OpenVPN\log" directory). 
# Use log or log-append to override this default. 
# "log" will truncate the log file on OpenVPN startup,
# while "log-append" will append to it.   Use one
# or the other (but not both). 
;log         openvpn.log
;log-append  openvpn.log

# Set the appropriate level of log
# file verbosity. 
#
# 0 is silent, except for fatal errors
# 4 is reasonable for general usage
# 5 and 6 can help to debug connection problems
# 9 is extremely verbose
verb 3

# Silence repeating messages.   At most 20
# sequential messages of the same message
# category will be output to the log. 
;mute 20

Client:
# Specify that we are a client and that we
# will be pulling certain config file directives
# from the server. 
client

# Use the same setting as you are using on
# the server. 
# On most systems, the VPN will not function
# unless you partially or fully disable
# the firewall for the TUN/TAP interface. 
;dev tap
dev tun

# Windows needs the TAP-Win32 adapter name
# from the Network Connections panel
# if you have more than one.   On XP SP2,
# you may need to disable the firewall
# for the TAP adapter. 
;dev-node MyTap

# Are we connecting to a TCP or
# UDP server?   Use the same setting as
# on the server. 
proto tcp
;proto udp

# The hostname/IP and port of the server. 
# You can have multiple remote entries
# to load balance between the servers. 
remote <server address> 3307
;remote my-server-2 1194

# Choose a random host from the remote
# list for load-balancing.   Otherwise
# try hosts in the order specified. 
;remote-random

# Keep trying indefinitely to resolve the
# host name of the OpenVPN server.   Very useful
# on machines which are not permanently connected
# to the internet such as laptops. 
resolv-retry infinite

# Most clients don't need to bind to
# a specific local port number. 
nobind

# Downgrade privileges after initialization (non-Windows only)
;user nobody
;group nogroup

# Try to preserve some state across restarts. 
persist-key
persist-tun

# If you are connecting through an
# HTTP proxy to reach the actual OpenVPN
# server, put the proxy server/IP and
# port number here.   See the man page
# if your proxy server requires
# authentication. 
;http-proxy-retry # retry on connection failures
;http-proxy [proxy server] [proxy port #]

# Wireless networks often produce a lot
# of duplicate packets.   Set this flag
# to silence duplicate packet warnings. 
;mute-replay-warnings

# SSL/TLS parms. 
# See the server config file for more
# description.   It's best to use
# a separate .crt/.key file pair
# for each client.   A single ca
# file can be used for all clients. 
ca <ca path>
cert <cert path>
key <key path>

# Verify server certificate by checking
# that the certicate has the nsCertType
# field set to "server".   This is an
# important precaution to protect against
# a potential attack discussed here:
#  http://openvpn.net/howto.html#mitm
#
# To use this feature, you will need to generate
# your server certificates with the nsCertType
# field set to "server".   The build-key-server
# script in the easy-rsa folder will do this. 
;ns-cert-type server

# If a tls-auth key is used on the server
# then every client must also have the key. 
;tls-auth ta.key 1

# Select a cryptographic cipher. 
# If the cipher option is used on the server
# then you must also specify it here. 
;cipher x

# Enable compression on the VPN link. 
# Don't enable this unless it is also
# enabled in the server config file. 
comp-lzo

# Set log file verbosity. 
verb 3

# Silence repeating messages
;mute 20

A:

Just for the record if someone comes here from search. 
I've recently reinstalled the OpenVPN server and all clients (also regenerating all the keys) and the problem went away.  I suspect this has been some kind of very localized and edge-case bug in server. 
Anyway, problem solved.