Reinstalled Windows 7 a few weeks ago and am now having issues with the sleep function. I have it set to go to sleep after 30 mins of inactivity and it will go to sleep by itself or if I press the sleep button. If I then press the on/off button on the front of my case it will wake up without any problems IF I do this within aprox 10 mins of it going to sleep. If I let it sleep any longer all it will do when the on/off button is pressed is spin up the fans and go to a black screen for an indeterminate amount of time. At which point I'm forced to hard reboot the machine and it will then boot normally. I've changed no hardware and made no changes to the Bios since reinstalling Windows 7. Does anyone have any suggestions for me? P.S. I'm using the latest video drivers, the same as before the reinstall.