Rogue Pick Pocket SK/paw Gnolls
 

If you have any of the lore item scrolls on you when you pick pocket a gnoll with the same one you will not be able to turn on auto attack or use certain skills. Targeting via left click doesn't seem to work either or /loot. You can still tab target, but it seems most skills will say "cannot activate ability right now" or something to that affect. Zoning and /camping resolves the problem.

I dont recall what does it but i know when you have a mob targeted with auto attack on and nothing is happening you can hit escape then retarget, always fixes it.

Well, that explains that. My rogue had that problem of not being able to attack the last time I played him in Split Paw. I will try him again sometime.