Strange Temperatures - Help Needed

I've just got a new system, amd xp2500+ on an asus a7v600 via kt600. I'm new to overclocking but have read a beginner guides and have set up my system with what seems to be sufficient cooling, 3 fans (1 intake, 2 exhaust) + psu fan (350W psu), and a thermaltake volcano 9 on the cpu. my temp for mobo and cpu under load are 27C and 39C respectively with no overclock. The big problem Im having is that when I run sandra and mb monitor they both tell me my power/auxilliary temperature is in the 120's!!! Sandra wont let me run the burn in wizard, and gives me these values

power/aux temp : 127 C
CPU fan speed 2909rpm (manually adjusted to this setting i get same problem on full 5200rpm)
CPU Voltage 1.74v
CPU Core Power 68W

I have read the sandra forums trying to find something to explain this with no luck. Whye would my aux temp be so high, when everything else is fine? Ive run the burn in a few times before with no troubles and all my bios settings are default, my computer seems completely stable, is this probably a bug in the program, or something i need to worry about. Can somebody please shed some light on this for me?

Alright, don't waste your time, I just started my computer, and despite the very cold air temperature, the power supply temperature remains at 127C, exactly the same value as before. The temperature is obviously not being read correctly.