I've got a mid 2007 Macbook Pro. 8600M GT graphics card. OS X 10.5.6. I had the the graphics card fail last year, and got a new logic board. Today, I was listening to some music in Front Row, when parts of the image on the screen disappeared. Music kept playing. I tried to exit with the Apple remote, it made sounds, but the screen was frozen. I tried a few force quit keyboard commands, eventually, it exited to the desktop. The time wasn't changing, so I assumed the computer had crashed. Then I got a bar appear across the top half of the menu bar, which alternated black and white. I held down the power button to restart the computer, and ran the hardware test, which came up with no problems. Crash log is below: Looks like some kind of graphics issue.