Sticking keys, repeating, when using keyboard

Sometimes when I'm using the keyboard, a key will get stuck until I press it again. Such as the brightness, I put it up once, and it goes up to full brightness, or typing something and it goes like thisssssssssssssss. The worst was when I had my headphones on, listening to music and I pressed the volume up once. The volume key repeated and went to max volume and blew my ears out. It's an early '08 mbp.
It's very annoying, and it seems to be getting worse, sometimes about every 10 seconds while using the keyboard. Is there any way to fix this? Thanks.

As a start to troubleshooting add a new User and log in there and see if the same thing happens. Report back to us.

I tried the guest user, and it still happens in there.