This has been reported a few times off and on. Some have had luck turning off Punk Detections altogether in the Carb Options page under the Social & Punks header. It may also be a corrupted file somewhere causing issues.
I haven't seen anyone be able to fully reproduce it yet. It just seems to occur randomly.
Another post on the same thing:
http://www.wowinterface.com/forums/s...light=speaking