Computer keeps coming out of standby/hibernation

[AncientPC]

I've just done a clean install of WinXP 64 and disabled WOL / wake on USB. If I boot up into the login screen and then put the computer into standby / hibernation, it will randomly turn on again. Is there any way to tell what's triggering the computer to turn back on?

 

[amdskip]

I don't believe so, what all is hooked up to it?

 

[ivanwolf]

Do you have a modem hooked to your home phone line? I have seen wake on ring issues before.

 

[AncientPC]

I took the system down to the basic components:

Externally: keyboard/mouse, 2 monitors, speakers, no USB devices (outside of mouse).

Internally: 2 hdd, floppy, dvd burner, video card, ram, cpu, no PCI or PCI-E cards.

 

[Fardringle]

Do you have an optical mouse? My old mouse used to sporadically activate itself (making the computer think it had been moved) and that would wake the computer up out of standby. Since unplugging a USB mouse won't hurt the computer while it's on, try disconnecting the mouse and see if the computer still wakes up on its own.