Why does "Turn Computer Off" = "Reboot" to BIOS

[rscpe]

Just recently installed new MB, CPU, VGA, blah, blah, blah
I partitioned/formatted my existing HDs and installed Win XP Home.
After a few reboots during additional hardware/software
installs, the system began to reboot instead of shutting down
upon shut down selection and subsequently enter
the BIOS (as if I had selected this during bootup).

Strangely, in the BIOS setup, it asks if I want to keep the setting of
1.15Mhz for my AMD 1800 rather than the normal setting of 1.53Mhz.

My new system specs as follows:

AMD Athlon XP 1800+
Asus A7V266-E KT266A AMD
Visiontek Xtasy 6564 Geforce3 TI 200
Creative Sound Blaster Live 5.1 Dolby Digital
Crucial Technology 256MB 184pin DDR PC2100
Power Man FSP350-60BN 350W AMD K7 ATHLON ATX PSU
Thermaltake VOLCANO 6Cu+ Fan Heatsink
DiamondMM SupraMax PCI K56 Modem
Windows XP Home

I don't know if there is a software/hardware conflict or some silly
12 level-deep check box that I accidently checked. The weird thing is
that in the BIOS (which is activated without my help) it asks if I want
to change the CPU speed??????

Thanks for your help!!!!

 

[splice]

Is there a jumper on the board for 100/133 FSB? And is it set correctly.

 

[DN]

There's a checkbox in WinXP that tells it to or not to reboot on errors -- uncheck it (I forget where it is) and you might get a better idea of why it's rebooting on shutdown..