Damn, a flame fest I wasn't apart of.... I am slacking lately.....
I will backup the bit about the same model of mobo's not reading the same temps etc.. I had 5 Epox 8K7A's and all of them read temps differently with the same parts installed. But the point is moot now.
What you want to go for is consistant relative temps but that is still not even close to accurate unless you have an accurate temp probe to calibrate from.
On my Abit KD7 the higher the temp rises the more inaccurate it gets. Once it gets past 42C it starts loosing .5C for every 2C past 42. So if the real temp is 44C it reports as 43.5C or 46C would report as 45C etc.... You can see how this will destroy any hope of usefull information with relative temps from a mobo. You need something to calibrate by. I use a DMM with the thermocoupler mounted under the CPU. Works OK but still not the best....
Bah, time for bed.