There are about 40 computers at work with this problem. They all have an ASUS P5KPL/1600 motherboard. They are all running SUSE Linux 11.1.
When I tell the computer to shutdown either through the UI or by issuing
shutdown -h now
in a root terminal, the computer wull shutdown for about 1 second and then powers back on again.
I have disabled all the wake on events in the BIOS just to make sure it's not an external event that's causing the computer to restart.
I've tried booting with an Ubuntu live CD to see whether the problem was with SUSE specifically. Shutting down from Ubuntu also doesn't work; the computer just restarts.
The IT guys at work tell me that the same machines (machines with the same motherboard) power down fine when Windows XP is installed.
If I boot the computer, enter the BIOS and save without making any changes, on the next reboot the computer will shutdown and stay off when told to do so from either SUSE or Ubuntu. After that, it goes back to rebooting every time it's suppose to shutdown.
Any ideas as to why I can't power them down with Linux?