[Galaxy Tab 8.9 General] trekker99:
I did some additional testing, and it seems that some part of the tab is functioning. I can get logcat and access adb shell even after the UI hangs. I have captured some logcats from booting up to after I switch on the wifi. The section below shows the AndroidRuntime crashing and restarting without success.

19:46:07.945 Debug AndroidRuntime 2491 Shutting down VM
19:46:07.945 Warning dalvikvm 2491 threadid=1: thread exiting with uncaught exception (group=0x40c321f8)
19:46:07.946 Warning WifiStateTracker 192 getNetworkInfo : NetworkInfo: type: WIFI[], state: CONNECTED/CONNECTED, reason: (unspecified), extra: (none), roaming: false, failover: false, isAvailable: true
19:46:07.946 Warning WifiStateTracker 192 getNetworkInfo : NetworkInfo: type: WIFI[], state: CONNECTED/CONNECTED, reason: (unspecified), extra: (none), roaming: false, failover: false, isAvailable: true
19:46:07.946 Info ActivityManager 192 No longer want app.processName (pid 1893) (adj 13) : hidden #26
19:46:07.947 Debug dalvikvm 2479 GC_CONCURRENT freed 604K, 11% free 7446K/8327K, paused 2ms+3ms
19:46:07.947 Info CrashReporterServiceDelegate 2452 Running task for: SystemJvm 10 reports (1 per task)
19:46:07.947 Error AndroidRuntime 2491 FATAL EXCEPTION: main
19:46:07.947 Error AndroidRuntime 2491 java.lang.RuntimeException: Unable to start receiver org.sopcast.android.ActionReceiver: java.lang.NullPointerException
19:46:07.948 Error AndroidRuntime 2491	at android.app.ActivityThread.handleReceiver(ActivityThread.java:2138)
19:46:07.948 Error AndroidRuntime 2491	at android.app.ActivityThread.access$1500(ActivityThread.java:127)
19:46:07.948 Error AndroidRuntime 2491	at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1209)
19:46:07.949 Error AndroidRuntime 2491	at android.os.Handler.dispatchMessage(Handler.java:99)
19:46:07.949 Error AndroidRuntime 2491	at android.os.Looper.loop(Looper.java:137)
19:46:07.949 Error AndroidRuntime 2491	at android.app.ActivityThread.main(ActivityThread.java:4512)
19:46:07.950 Error AndroidRuntime 2491	at java.lang.reflect.Method.invokeNative(Native Method)
19:46:07.950 Error AndroidRuntime 2491	at java.lang.reflect.Method.invoke(Method.java:511)
19:46:07.950 Error AndroidRuntime 2491	at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:978)
19:46:07.950 Error AndroidRuntime 2491	at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:745)
19:46:07.951 Error AndroidRuntime 2491	at dalvik.system.NativeStart.main(Native Method)
19:46:07.951 Error AndroidRuntime 2491 Caused by: java.lang.NullPointerException
19:46:07.951 Error AndroidRuntime 2491	at org.sopcast.android.ActionReceiver.onReceive(Unknown Source)
19:46:07.951 Error AndroidRuntime 2491	at android.app.ActivityThread.handleReceiver(ActivityThread.java:2131)
19:46:07.951 Error AndroidRuntime 2491	... 10 more
19:46:07.951 Info CrashReporterServiceDelegate 2452 Running task for: DataJvm 10 reports (1 per task)
19:46:07.952 Info CrashReporterServiceDelegate 2452 Running task for: SystemAnr 10 reports (1 per task)
19:46:07.952 Warning WifiStateTracker 192 getNetworkInfo : NetworkInfo: type: WIFI[], state: CONNECTED/CONNECTED, reason: (unspecified), extra: (none), roaming: false, failover: false, isAvailable: true
19:46:07.952 Warning WifiStateTracker 192 getNetworkInfo : NetworkInfo: type: WIFI[], state: CONNECTED/CONNECTED, reason: (unspecified), extra: (none), roaming: false, failover: false, isAvailable: true
19:46:07.952 Info CrashReporterServiceDelegate 2452 Running task for: DataAnr 10 reports (1 per task)
19:46:07.952 Info CrashReporterServiceDelegate 2452 Running task for: SystemTombstone 10 reports (1 per task)
19:46:07.953 Debug comsamsungapp 2367 [MSC]>>> StockClock_Integration.java:146 [0:0] onReceive com.sec.android.widgetapp.stockclock.UPDATE
19:46:07.953 Info CrashReporterServiceDelegate 2452 Running task for: DataTombstone 10 reports (1 per task)
19:46:07.953 Info CrashReporterServiceDelegate 2452 Running task for: Js 10 reports (1 per task)
19:46:07.953 Info AmazonAppstore.UpdateService 2452 Received action: com.amazon.mas.client.framework.UpdateService.CONN_CHANGED from intent: Intent { act=com.amazon.mas.client.framework.UpdateService.CONN_CHANGED cmp=xxxx (has extras) }
19:46:08.068 Debug comsamsungapp 2367 [MSC]>>> StockClock_Integration.java:153 [0:0] onReceive : no stock widget!!!
19:46:08.069 Debug CrashReporterServiceDelegate 2452 Processed 0 DataAnr report(s)
19:46:08.069 Debug CrashReporterServiceDelegate 2452 No reports remaining to process for DataAnr, completing task
19:46:08.070 Debug CrashReporterServiceDelegate 2452 Processed 0 SystemAnr report(s)
19:46:08.070 Debug CrashReporterServiceDelegate 2452 No reports remaining to process for SystemAnr, completing task
19:46:08.071 Debug CrashReporterServiceDelegate 2452 Processed 0 DataJvm report(s)
19:46:08.071 Debug CrashReporterServiceDelegate 2452 No reports remaining to process for DataJvm, completing task
19:46:08.071 Debug CrashReporterServiceDelegate 2452 Processed 0 SystemJvm report(s)
19:46:08.072 Debug CrashReporterServiceDelegate 2452 No reports remaining to process for SystemJvm, completing task
19:46:08.072 Error android.os.Debug 192 !@Dumpstate > dumpstate -k -t -n -z -d -o /data/log/dumpstate_app_error
19:46:08.072 Debug CrashReporterServiceDelegate 2452 Processed 0 DataTombstone report(s)
19:46:08.073 Debug CrashReporterServiceDelegate 2452 No reports remaining to process for DataTombstone, completing task
19:46:08.073 Debug CrashReporterServiceDelegate 2452 Processed 0 SystemTombstone report(s)
19:46:08.074 Debug CrashReporterServiceDelegate 2452 No reports remaining to process for SystemTombstone, completing task
19:46:08.074 Debug CrashReporterServiceDelegate 2452 Processed 0 Js report(s)
19:46:08.074 Debug CrashReporterServiceDelegate 2452 No reports remaining to process for Js, completing task
19:46:08.075 Info dumpstate 2513 begin
19:46:08.075 Debug PowerManagerService 192 mIsLockZone = true
19:46:08.196 Debug dalvikvm 2479 GC_CONCURRENT freed 1200K, 17% free 7552K/9031K, paused 2ms+2ms
19:46:08.322 Debug PowerManagerService 192 mIsLockZone = false
19:46:08.323 Debug dalvikvm 2479 GC_CONCURRENT freed 1216K, 17% free 7667K/9159K, paused 2ms+2ms
19:46:08.552 Debug dalvikvm 2479 GC_CONCURRENT freed 1194K, 16% free 7751K/9223K, paused 2ms+3ms
19:46:08.553 Debug /Ln.java:220 2479 19:45:55.205 main Configuring Logging, minimum log level is INFO
19:46:08.553 Info AmazonAppstore.SimpleObfuscator 2479 Pre-moar JB mode: Using default provider.
19:46:08.553 Info AmazonAppstore.CmsImageStore 2479 CmsImageStore() - imageStorePath="f5db9b6b3a47850f57e6cb55f1cd416786176410f8363c85788e3a77d2804850"
19:46:08.553 Info AmazonAppstore.CmsImageStore 2479 CmsImageStore() - imageStoreDefaultPath="f9a69ab4260180788d2f7689e1c131bf85b6c8a61e03dbd8f8441376ccc37f6f"
19:46:08.554 Warning AmazonAppstore.ImmediateDispatcher 2479 Attempted to dispatch message to empty observers
19:46:08.554 Warning AmazonAppstore.ImmediateDispatcher 2479 Attempted to dispatch message to empty observers
19:46:08.554 Warning AmazonAppstore.ImmediateDispatcher 2479 Attempted to dispatch message to empty observers
19:46:08.555 Warning AmazonAppstore.ImmediateDispatcher 2479 Attempted to dispatch message to empty observers
19:46:08.555 Warning AmazonAppstore.ImmediateDispatcher 2479 Attempted to dispatch message to empty observers
19:46:08.555 Warning AmazonAppstore.ImmediateDispatcher 2479 Attempted to dispatch message to empty observers
19:46:08.556 Warning AmazonAppstore.ImmediateDispatcher 2479 Attempted to dispatch message to empty observers
19:46:08.556 Warning AmazonAppstore.ImmediateDispatcher 2479 Attempted to dispatch message to empty observers
19:46:08.556 Warning AmazonAppstore.ImmediateDispatcher 2479 Attempted to dispatch message to empty observers
19:46:08.557 Warning AmazonAppstore.ImmediateDispatcher 2479 Attempted to dispatch message to empty observers
19:46:08.557 Warning AmazonAppstore.ImmediateDispatcher 2479 Attempted to dispatch message to empty observers
19:46:08.680 Debug dalvikvm 2479 GC_FOR_ALLOC freed 542K, 16% free 7926K/9351K, paused 25ms
19:46:08.681 Debug WifiService 192 acquireWifiLockLocked: WifiLock{UpdateService type=1 binder=android.os.BinderProxy@41fac080}
19:46:08.681 Info dalvikvm 2452 Total arena pages for JIT: 11
19:46:08.681 Info dalvikvm 2452 Total arena pages for JIT: 12
19:46:08.682 Info dalvikvm 2452 Total arena pages for JIT: 13
19:46:08.682 Info dalvikvm 2452 Total arena pages for JIT: 14
19:46:08.682 Info dalvikvm 2452 Total arena pages for JIT: 15
19:46:08.683 Info dalvikvm 2452 Total arena pages for JIT: 16
19:46:08.683 Info dalvikvm 2452 Total arena pages for JIT: 17
19:46:08.684 Info dalvikvm 2452 Total arena pages for JIT: 18
19:46:10.225 Debug PowerManagerService 192 mIsLockZone = true
19:46:10.459 Debug PowerManagerService 192 mIsLockZone = false
19:46:11.003 Error su 2527 sudb - Opening database
19:46:11.132 Error su 2527 sudb - Database opened
19:46:11.133 Error su 2527 sudb - Database closed
19:46:11.252 Warning WifiStateTracker 192 getNetworkInfo : NetworkInfo: type: WIFI[], state: CONNECTED/CONNECTED, reason: (unspecified), extra: (none), roaming: false, failover: false, isAvailable: true
19:46:11.490 Debug AndroidRuntime 2529
19:46:11.491 Debug AndroidRuntime 2529 >>>>>> AndroidRuntime START com.android.internal.os.RuntimeInit <<<<<<
19:46:11.491 Debug AndroidRuntime 2529 CheckJNI is OFF
19:46:11.491 Debug AndroidRuntime 2529 setted country_code = USA
19:46:11.492 Debug AndroidRuntime 2529 setted sales_code = XAR
19:46:11.492 Debug AndroidRuntime 2529 found sales_code tag = <XAR>, </XAR>
19:46:11.613 Debug LibQmg_native 2529 register_android_app_LibQmg
19:46:11.614 Debug AndroidRuntime 2529 Calling main entry com.android.commands.am.Am
19:46:13.358 Verbose AlarmManager 192 waitForAlarm result :8
19:46:13.359 Debug BatteryService 192 update start
19:46:13.359 Debug BatteryService 192 level:82 scale:100 status:3 health:2 present:true voltage: 4030 temperature: 330 technology: Li-ion AC powered:false USB powered:true icon:17302822 invalid charger:0
19:46:14.252 Debug SupplicantStateTracker 192 CompletedState{ what=147462 when=-1ms obj=android.net.wifi.StateChangeResult@42499b88 }
19:46:14.253 Info wpa_supplicant 2293 WPA: Group rekeying completed with 28.41.FC [GTK=CCMP]
19:46:16.015 Debug PowerManagerService 192 lightSensorChangedLocked 10
19:46:16.015 Debug PowerManagerService 192 lcdValue 42
19:46:16.016 Debug PowerManagerService 192 buttonValue 0
19:46:16.016 Debug PowerManagerService 192 keyboardValue 0
19:46:16.016 Debug PowerManagerService 192 lightSensorChangedLocked : mKeyboardLight : 0
19:46:19.318 Error Watchdog 192 !@Sync 25
19:46:21.085 Error su 2539 sudb - Opening database
19:46:21.085 Error su 2539 sudb - Database opened
19:46:21.085 Error su 2539 sudb - Database closed
19:46:21.207 Debug AndroidRuntime 2541
19:46:21.208 Debug AndroidRuntime 2541 >>>>>> AndroidRuntime START com.android.internal.os.RuntimeInit <<<<<<
19:46:21.208 Debug AndroidRuntime 2541 CheckJNI is OFF
19:46:21.208 Debug AndroidRuntime 2541 setted country_code = USA
19:46:21.209 Debug AndroidRuntime 2541 setted sales_code = XAR
19:46:21.209 Debug AndroidRuntime 2541 found sales_code tag = <XAR>, </XAR>
19:46:21.328 Debug LibQmg_native 2541 register_android_app_LibQmg
19:46:21.328 Debug AndroidRuntime 2541 Calling main entry com.android.commands.am.Am

Interestingly enough, the AndroidRuntime fails to continue after the following errors from sudb.

19:46:11.003 Error su 2527 sudb - Opening database
19:46:11.132 Error su 2527 sudb - Database opened
19:46:11.133 Error su 2527 sudb - Database closed

I see this happening continuously until I reboot.

As I rebooted the tab a few times and noticing that Sopcast being involved in the RuntimeException in all cases, I uninstalled the app and switched on wireless.

So far it seems to be working!! It does look like my initial intuition was correct, and I have some logcats to back it up. Anyone knows why the whole AndroidRuntime was taken out of commission?

*edit*

I am also wondering why Sopcast doesn't crash AndroidRuntime when it is not rooted. Any insight?