This is another one that should be on the top of the list.

If Im puller in a group every now and then I just can not attack a MOB. Sometimes if I take my gun off, target a team mate, attack (message:cannot attack team mate), hit ESC, put my gun back on its fine. (but a HUGE PITA) Then sometines like last night no matter what I do I can not attack.

again...ETA????