I'd post error messages if I had them, but no errors show up in Bugsack right now for me when this problem occurs.
At random, my action keys will refuse to respond to their bindings. I can't even use them by clicking on them with my house cursor.
Reloading the UI will not fix the problem.
Only doing a full client restart will solve this problem.
I have tried to pay attention to what I am doing and what is happening in game when this problem occurs, but unfortunately I haven't noticed anything specific. It just happens at random and I am not sure if there is a way to fix it OR if this problem has been posted about before here. If it has and I missed the thread, I am sorry.
Edit: After finding this thread
http://www.wowinterface.com/forums/s...ad.php?t=13952 I determined what was happening. I have key bindings, somehow, assigned to switch my action bars however there was no visual indication on my bongos action bars. After using the binding and moving up one action bar, trying a key binding out and watching it not do anything, then going back down to the other action bar with the other key binding and being able to use the key bindings on my action bars again I found out the problem. Sorry about the thread then, I do hope this helps any other though.