I have the exact same problem, monitor never comes back after sleep and have to hard reboot. EX58-UD5-F7 bios, XFX 285 videocard, 6 gigs high-end ram, 920 chip. Problem happens with both Vista and W7, all drivers are current. Don't have any extra parts so any help should not involve trying new parts. I bought the best stuff to begin with, and everything else works fine. Thanks in advance for any help that might be given.