Well i just got wow on the computer so thats not the problem.. :/ Did get a 48 houres bann for 4 days ago too when i was botting my 80 warrior in bgs when i was sleeeping.
This only happens to me after i start and stop HB a few times. Usually i'll stop it between instance runs. I then have to reboot my pc to make sure the game doesn't crash at some point later on.