Unplug it, leave it unplugged plug it back in 30 seconds later then turn in back one 30 sec after this resets the whachamajoggs. (For the Macbook pro take out the battery)
Reset the PRAM silly thing but often works when for no apparent reason they start doing stupid things. Option Alt P R I think it is…hold them down at restart and keep them held down till you’ve heard the chime a few times.
I’ve no idea if these will help, but to be honest I’m about sick of Mountain Lion and it’s glitches I’m got a Mac pro and twin Cinema screens Photoshop will lock out, cursors will vanish in InDesign from one screen to the other or just Buzz and flicker.
I’ve not had one problem and I swore it ran faster in Snow Leopard (which I reckon was their best OS since back in the day)