The pause and speed altering hotkeys in battle are unreliable.
Many times when I tried to use them the effect would toggle twice, e.g. pausing and then instantly unpausing. It's not a case of holding the keys down too long; this happens even when the keys are only tapped lightly. The problem is not constant; about half the time the hotkeys do work as expected. The interface shortcuts work correctly, but in the minimal UI those buttons are missing. This isn't a frame rate relayed issue either; it happens in both large and small battles.

There was a thread about this a few months back; no solution was found.