Graphic jitters on screen, freezes macbook, startup problems

As I said above.

When the macbook freezes the only way is to push the power button until it shuts off. When it first started happening about three weeks ago I could just power it back up and nothing more happened. Lately it got stuck during the boot up (the blue screen after the white screen wit hthe apple)and now I have this weird graphical "error", like a bar of broken up lines on top of the screen during startup. It then goes into a message of "Please restart your computer, hold down the power button and then push it again". When I do that it just loops until that same message. I've tried different startup commands but nothing gets me past that. When I upgraded and reinstalled mac os x to snow leopard i got it working again. For about 4 days and now I'm stuck with that same message. I can only conclude that it has something to do with a hardware failure.

I got a 2,2 GHz A1226 model. Also I've had issues with the superdrive not being able to write dvd/cds but reading them since about a year back. Related?

Any thoughts or suggestions would be greatly appreciated.