It appears I'm having a similar problem to the folks on this thread...at startup (within a few minutes) my Sapphire 5770 card will do the vertical line thing. It happens on both Windows 7 Home Premium 64-bit and Windows XP Pro 32-bit. Drivers are ATI CCC 9.12. Have latest MB Bios, checked memory (RAM), checked hard drives, turned off power management, etc. etc. etc. Still have the problem. Used ATI overdrive to increase the initial GPU and Memory clock values from 157MHz:300Mhz to 400Mhz:900Mhz and still have problems. Board runs at ~36 degrees idle, and stays under 60 degrees when running stress tests. A very temporary workaround is: once the problem occurs and locks up the system: shutdown the system, wait a few seconds and turn off the power supply, wait a few more seconds and turn on the power supply, and restart the system. I have never had the problem reappear after the power cycle, but once you shutdown again (or system goes in sleep mode) for more than a few minutes, all bets are off! My Configuration: MB: Gigabyte GA790XTA-UD4 CPU: AMD Phenom X4 945 Memory: 4GB OCZ (2 2GB chips) HDs: 2 1TB seagates (SATA) Video: Sapphire HD5770 I've tried to fix the issue for more than 1 month with no luck. Time to RMA the card and go Nvidia.