Had the same issue, when I pulled the heatsink I found contaminates imbeded in the copper of the heat sink that came with the chip in the box , little gray metalic chunks when you look at them with a magnifying glass. Bad thermal pad Im thinking, managed to remove them from the copper and get the ridges it caused smoothed out and reinstalled with some fresh goo , idles at 41c now
Sounds like you did a poor job mounting the heatsink, or you've got very bad case airflow/high ambient temperature. I overclocked my Phenom II X4 940 to 3.5Ghz using 1.375V and I don't exceed 60C during a prime95 torture test. My ambient temp is usually 70-75F.