Windows XP HE SP3. The BIOS of this Mainboard only has S1(POS) or S3(STR) as choices in Power Management, not Disable or else. In either mode, when I have used SBy or Hibernation, the PC will only bootup again after some twenty minutes. Keyboard wake-up enabled or not. Strange thing: after about 15 minutes, when pushing the on/off swith, the Power- and HDD-LED's light up very shortly, and the CPU-fan make sa little move; that's all. A very strange situation that the mainboard or the O/S waits so long to reboot. Also very strange that this problem appeared out of the blue; all worked perfect till a week ago. No overheat; also after three minutes use. No Virus or anything according Norton IS. How can I get rid of this very strange problem?