There were known NVidia graphics hardware defect issues with MBPs of roughly that vintage, so if that was the problem, you should have received similar service even if you were not covered by the AppleCare extended warranty.
Mine was a ATI chip unfortunately. The problems were all in the end related to a broken latch - broken latch interfered with sleep mode, which meant that occasionally the laptop would spend a few hours in a laptop sleeve, fans going full blast, failing to go to sleep. I'm pretty that cooked the VRAM and DVD drive.
The non-unibody MBPs had a lot of functionality tied to the ridiculously complex lid latch. If the latch broke the laptop was SOL.