Speedfan and Temp questions

Back story to this problem:

Playing Rise of nations the game would crash randomly all the time, but only while playing RON. According to microsoft it's some sort of unfixable memory hole that thousands of people will experience, but they can't do antying about it.

My brother calls me up, he's a GS manager, and tells me that a computer they just had in has been crashing in Civ4, another microsoft game, just like mine, and they swapped all kinds of hardware looking for the problem. That still didint' fix the problem. Then they took a IR thermal probe and looked for sources of high heat, maybe it was causing the computer to crash. Sure enough the south bridge on the computer was running about 90*C when the game was playing, so they put a small HSF and on it and it stopped crashing and they could finally play the game.

So my question is, i installed speedfan so i can monitor all the levels of heat for each component on the MB. Unfortunately they aren't labeled so i was wondering if anybody knew of a place that can identify the different heat sources for me. There is one temp in speedfan that shows 117*C!!!! I hope to god that's not my southbridge.

Here's the PC specs:
AMD Athlon XP 3200+
Asus A7N8X Deluxe Vers 2.0
1gig Corsair XMS
eVGA 6800GT
SB Audigy 2
2x200 gig WD HD's in FW raid 0.
550 W PS.