I have a 2009 mac pro. Upgrades: 5870 in addition to gt120 Additional Apple Ram 5 port USB pci card I've had it for almost 2 years and never had a problem. I've been using the same hardware for 1 year. No problem. I updated to 10.6.8. Let the problems begin. First, the installation was botched. It downloaded, ran, said it need to reboot to complete. It wouldn't shutdown. It just gave me a spinning status wheel (not the beach ball) on the GT120 monitor. I waited an hour. Forced it off by hitting the power button. Rebooted and everything seemed fine. Except for Time Machine. It said there was 1,000,000+ files to back up. Strange, but I didn't panic. 4 hours later, and it had backed up 250 mb of data. I thought my time machine hard drive was having issues. Reformatted another drive, and decided to start a fresh time machine instance. Same problem. 4 hours and 250 mb of 720GB backed up. I tried to reboot. It does the same thing as the installation: just a spinning status wheel on the gt120 monitor. The other monitor is just a blue screen without the wheel. I had no issues with 10.5 --> 10.6.7. I'm running tech tools deluxe right now. I'll update with a status after it runs. Has anyone else encountered this problem? Does anyone have any ideas on how to fix it? Thanks!!!!