Apparently OpenVPN only allows CBC (copy-pasted from logfile):

Sun May 18 00:24:18 2014 Cipher 'AES-128-CFB1' uses a mode not supported
by OpenVPN in your current configuration.  CBC mode is always supported,
while CFB and OFB modes are supported only when using SSL/TLS
authentication and key exchange mode, and when OpenVPN has been built with
ALLOW_NON_CBC_CIPHERS.