Windows 2000 restart now hangs after BIOS flash

I was having some video card & issues with my Soyo SY-6BE+ mobo so I
flashed the Bios to the latest revision. It came back up fine on reboot
and resolved the issues, but now I just get a black screen when I
restart Win2k.

If I unplug the machine to shut it down and then plug it back in I can
reboot OK. It will continue to boot fine if I only choose "Shut Down"
and then turn the machine back on, but hangs if I use restart. I tried
clearing the CMOS and reloading defaults but it didn't help. APM is
enabled (system CPU is a PIII 450).

Any suggestions are appreciated...