I don't do so great with these great metal beasts... so be warned... however...
My dear puppy LOVES to bash my keyboard with his feet while wrigling upside-down with his tennis ball in his mouth... or leap over my laptop, scrabbling at my keyboard in the process... you get the idea...
It's usually always the F-keys. On rare occasions it's been some weird combination of keys that has done it. One incident took me days to figure out, by pressing all sorts of keys. If this doesen't work, I suggest you go to your computers help bar and check the info on F-keys and keyboard shortcuts.
I'm thinking your problem sounds alot like one I had... the fix was in the super secret hidden *screen* menu. I just now tried a bunch of different combos to get the screen to come up ... I was messing too many things up, so I'll leave it for you to find. It's the little pop-up menu that controls alot of things regarding your screen and magnification, ect.
