Reboots instead of Suspend

I have an interesting problem. I have a system that reboots instead of going into suspend when the screen saver under Windows is turned on. It does a proper suspend when the screen saver is set to none. Varying the time of the screen saver and video suspend does not effect the problem.
OS: Windows 98 SE (fresh load)
Hardware:
MOBO DFI AK-74SC (VIA KT133 Chipset)
Processor Athlon 800 Socket "A"
Memory 128 Meg PC100 CAS 3 (with SPD)
Video ATI Expert99 16MEG (Rage128 Chipset)
Audio SoundBlaster PCI 128
Modem PCI Pine with ESS 2838 Chipset (winmodem)
I have tried 3 different BIOS from DFI.
Two different Video Drivers from ATI.
I have tred disableing ACPI & APM in BIOS, both separately and together.
I have no IRQ confilicts and no confilicting or disabled devices under Device Manager or System Information.
Any one got any ideas?

Has this always happened? Or has it just started recently? If just recent, then have you installed something lately? If you have then uninstall the app or what ever then restore *.DA0 file to restore the registry.

New machine a customer just ordered this configuration.

Update on this problem. The Mobo design engineers in Taiwan have narrowed it down to yet another VIA & ATI conflict. The New VIA 4-in-1 1425A changes the problem to a system hang in suspend vice a Reboot. Interesting the guys in Taiwan tell me you on get this problem with certain screen resolutions and color setting. 800 X 600 16 bit high color you hang, go 32 bit true color and it works fine. VIA & ATI have been notified but they have not replied. Probably will not either.