lowtcell: Your idle temps look appropriate. Can you re-run your load temps, preferably with Prime small FFTs? The link for that data is missing in your above post.

HeinzS: I also have a P5B Dlx and I can confirm that the CPU reported temps for that board are sometimes out to lunch. Your E8400 idle core temps look a little too high which is why my E8400 needs to run a Idle0=-2 correction factor on both cores for better accuracy. You also might have the sticking sensor issue where they simply won't go any lower than a fixed value even if you move to the North pole.