Weird reboot on SY-KT400 Dragon Ultra Platinum

Has anyone ever had a problem similar to this? My system runs fine but all
warm reboots result in Windows XP Pro seeing the Athlon XP as 1/2 speed and
the system runs very very slowly as soon as Windows starts to boot. After
any software install that requests a reboot or a game freeze, I must shut
down completely for about 15 minutes and then everything works normally
again. I have speculated that the system must cool down a bit before it will
boot properly. (??) All of the fans are
spinning. Soyo HW monitor shows tha the voltages are OK and CPU temp is
about 135F and chasis 94F with low stress use. I'm just wondering if anyone
else has ever experienced this. I've been putting up with it for 18 months.

SY-KT400 Dragon Ultra Platinum (bios K7VX4-2AA3)
Athlon XP 2100+ with retail AMD fan (Detected as 1.73 GHz in System
Properties but after a reboot it's 866 MHz))
Kingston DDR333 512 MB
ATI 9600 Pro 128MB video card
2 80mm case fans
Enermax 350W power supply with 2 fans
Sigma box card reader
1 physical hard drive (W.D.) and 1 floppy
2 CD/DVD decks

 

There was a bios update to address this issue. Version 2AA5 or above if
I remember correctly.