GAMEPLAY: Everything but chat shutting down

Ive had an issue where all i can do in game is chat. sometimes it will still let me move, sometimes it won't. but all of the hotkeys are broken, and my spells won't cast. i have fixed it a couple of times by hitting my shift key several times, thinking it might be a sticky keys thing, but that dosnt work all the time. also, i use a mac, and I'm not sure if mac has sticky keys? anybody else had this issue?