Different temp sensors

I have an asus A7V133-C rev. 1.05. <----dot, wih an athlon 1800 palamino. I had Asus probe and MBM reading the CPU temp before and I was geting the same high temps in both (around 52°C idle and 60°max load). I tried speedfan today and if I understand the reading right I am now at 48°C. The thing I dont get is the way it lists the temps. There are a few readouts that are ridiculously high and have a flame symbol next to them. One says 76°C and two others say 144°C! I assume they are the max temps allowed because if they were actual redings I think my comp would be on fire. so is it the one that has a tick nex to i that is my CPU temp? Because that is a 48°C so it would be more likely than the flaming 76C one.
Sorry this is so long winded but I need help working out which Temp I should be looking at. Thanks to anyone who can help.

I'm not sure. I have a A7N8X-DLX from asus, and i tried out Speedfan and also saw that all the temps are different from what Probe and MBM read. I'd just stick w/ MBM.

Someone on here said tha speedfan read the temps direct from the bios hough, and that is about the same temp I get when I check bios reading. i would have thought that would be more accurate. Or more honesrly I hope thats more accurate so I dont need another new heatsink.