CS5, holding the spacebar shortcut not working?

Blame Firefox... No shit.

I have a brand new imac intel i7 27" and have installed photoshop cs5, but the spacebar hand tool is not working. any ideas? the hand tool and all other tools work, just the shortcut key of holding the spacebar doesn't work.

"I've been having the same problem and by accident discovered that my spacebar short cut didn't work if I had my Firefox browser open. So if you are running Firefox by any chance while working in Photoshop CS5 - close it. I ran Safari instead and the hand tool works if that browser is open."