I've have been having sleep issues lately with my upgraded 4,1 to 5,1 MP, tried everything I could think of to figure out why it wouldn't sleep, so my last resort before heading to the forums was to see if I could boot from the AHT disc that came with my MP. I didn't expect it to work since I've read others trying since upgrading their firmware and hardware to match, but I was totally shocked that it booted and tested. How can this be?, did Apple do something in either 10.7 or 10.8 to let this happen or is this just a fluke. I'm currently running 10.8.2, firmware MP51.007F.B03, with a Xeon 3680, Apple ATI Radeon 5870, 12GB of PC10600 DDR3 ECC 1333MHz. I did get and error when it came to the video controller, error 4vdc/3/40000003:video controller, other then that the memory tested OK, and the logic board OK, the first test I ran was the extended so it checked the fans as I heard them rev up, the only test that it didn't run was the video, which I believe is the last test, and runs the color gamut. I'm still scratching my head on this one, can anyone else give this a whirl with a 2009 upgraded firmware and CPU and see if it boots and runs? One thing I did notice, it was saying I had 8 cores when I have 6, and 5870 came up as unknown, which might be why it didn't run video test. My graphics card has been working fine, but the past few days my Mac won't sleep.