This is different from a crash or disconnect. With this you are just moseying along and everything just stops. Then 10-20 seconds later, everything starts again. So apparently the network is still talking as you don't time out. Seems to be random as well. Yesterday it happened to me twice while sitting in dock (different ones).
I think its your client image that freezes. I turned off the windows options for recording and screenshots (in the same game mode screen) and its only been a day, but no freeze ups.