GPU crapping out? help please!

My laptop (almost 4 years old) has a Radeon 9000 GPU that I think is having problems. I think it's a hardware problem, but I'm not sure and I'm hoping someone here will know more than me about it. Okay, here's what's going on:

I started it the other day and it booting failed with a BSOD saying that the driver was stuck in an infinte loop. The file referenced was an ATI driver file (atidvag, I think). I was able to boot it in safe mode, after which it started fine in normal mode. The next day, it would not boot at all in normal mode until I removed the drivers in safe mode. To be sure the drivers were removed, I deleted all ATI files and removed all ATI references from the registry. After reinstalling the drivers, the system crashed when I tried to change the resolution to the LCD's native resolution and again it wouldn't boot in normal mode.

I was able to get it to run normally for a short time. I won't bother saying how because it only lasted a few reboots and repeating the process didn't work again. Now, it will not run at all with the ATI drivers installed, but it runs with the generic Windows drivers (which aren't acceptable because I cannot run at the display's native resolution and scrolling performance is HORRIBLE).

On a few occasions in last few months the display has become corrupted after being on for a few hours. Today I left the computer for a little while and when I came back, the image was very corrupted and I could see by the size of the task bar that the resolution had been reset to 800X600 or 640X480. There was some error message on the screen, but I couldn't read it.

I'm inclined to think that some part of the GPU has become faulty. Is it possible to have a problem in the GPU that would allow functionality with the generic Windows graphics drivers, but not the the full functionality of the ATI drivers? Any other thoughts on what the problem could be?