but I've had vertical striping once, a few blank screens after disconnecting the AC adapter, and a few occasions of blasted contrast (that lasts for about a minute). I admit I didn't have the disk and used Apple Hardware Test off the EFI chip (holding down F2). Do you think Apple Hardware Test is conclusive and 8600M isn't defective or should I take it into Apple? It seemed to just test memory and the logic board, but I could be wrong. and i didnt perform extensive testing. People said they run a test that has colors all over the screen, the Apple Hardware Test I ran was just a blue screen and a button. Also, when I ran the Doom 3 demo with 1152x768 resolution (on Leopard), it ran terribly with real low fps (not sure if it's like that for all 8600M but I heard dying ones get terrible fps) HELP???