When it happens if I'm in a group of monsters, for some reason I can't use any skills. Here's the stranger part, THEY CAN'T KILL ME! I actually walked away from my computer when this happened as I was just about to mop up an elite, I came back 30 minutes later and they were still wacking away bringing my health to 1 but never killing me.
So I had my friend join my game and to see if he could kill them for me hoping it would free me up. Well he popped in, cleared it pretty quickly but I was still stuck. I could rotate but I couldn't actually move or use abilities/switch gear/potions/etc.
So he gets the idea and says "Try to TP". My buddy and I never laughed so hard in our lives when I pressed "T". My barbarian ASPLODED as soon as I tried to TP and was greeted with the good 'ol death screen.
Didn't know if this bug is related to server lag or just a programming glitch. If I can replicate this issue and record it I will do so and report back here.