I am using Fedora Core 5 with the standard kernel (2.6.17-1.2185_FC5smp
currently). I am having trouble getting suspend to work. This is a desktop
computer, not a laptop.

When I choose Suspend from the Gnome System menu, my computer powers off,
but then a split second later, before the fans have even stopped spinning,
it powers right back on. This works correctly under Windows XP. Normal
shutdown works correctly, properly powering the system down.

This is what dmesg shows after a suspend:

----------begin dmesg----------
PM: Preparing system for mem sleep
Freezing cpus ...
Breaking affinity for irq 0
CPU 1 is now offline
SMP alternatives: switching to UP code
CPU1 is down
Stopping tasks: =================================...===|
pnp: Device 00:09 disabled.
pnp: Device 00:07 disabled.
pnp: Device 00:06 disabled.
PM: Entering mem sleep
Intel machine check architecture supported.
Intel machine check reporting enabled on CPU#0.
CPU0: Intel P4/Xeon Extended MCE MSRs (12) available
CPU0: Thermal monitoring enabled
Back to C! PM: Finishing wakeup.
----------end dmesg----------

System Information

* P4 desktop with Asus P4P800-E motherboard.
* Fedora Core 5 with latest updates.
* ATI Radeon 9000 Pro
* One 120M IDE disk
* One ATA CD/DVD combo drive
* Motherboard AC97 audio
* D-Link DWL-G520 Wireless PCI network adapter
* Hauppaugue WinTV

BIOS configuration

* ACPI enabled
* APM disabled
* Suspend mode tried both "Auto" and "S3 only"
* Power on by (RTC, Modem, etc.) all disabled
* ACPI 2.0 Support tried both yes and no
* ACPI APIC Support tried both yes and no

Any help would be appreciated.