I'm having a little trouble seeing your second screenshot here at work, but it looks like you have a definate cooling problem. I don't have an 8600, so I don't know what the P-M's are supposed to max out at (temperature wise), but Intel's specs for my 3.0 Ghz P4 HT is 69.1 C max.
Your processor temp is 67 degrees, and mine's never gotten that high. I never could locate the specs for any of ATI's vid cards, but I just always assumed that any temperatures higher than my processor would be bad. It appears your GPU temp is 75 C.
Have you checked to make sure the fan(s) are even coming on?
Try going into FanGui and just setting them to high manually. If you can't hear them when you make that change, then they aren't coming on. If you can hear them, leave them on, then go play games. Then come right back and check the temps after you play for awhile, and see where they are at. Just a few suggestions.