Computer enters sleep, then immediately wakes up again

[Naujoks]

I hope I'm in the right area of the forum.
I have the Asus AB9 mobo with an Intel Core 2 E8500 CPU, running Vista 32 Ultimate.
When I try to put the computer to sleep, everything seems to be working fine, until the computer actually cuts off the power (no lights, fans etc). But this only lasts for 1 second, and then the computer immediately wakes up again! I just can't figure out how to keep it asleep.

Does anyone have an idea what I could try? Theoretically the mobo should support sleep mode, and I have the relevant BIOS entry enabled.

 

[Guest]

you must have the wake up from usb enabled in the bios, disable it and you should only be able to wake up from the power switch