Out of interest, what are you using to measure these temps? Bear in mind that the on die (per core) temps on Phenom 2 systems are not accurate temps. You need to use a program like Hardware Monitor to look at the single CPU temp, as that is more accurate.
For instance, I am running an 1100T at stock speed. Core Temp reports an average of 21c idle. Hardware monitor also reports this approx temp across the cores but lists the CPU temp as 30c. Since the room isn't being air-conned at present, the actual temp is 30c.
Under load both temp readings will rise. As the actual temp rises, the difference between the two temps (per core, and overall CPU) decreases, but the CPU temp is still the important one if you're concerned about thermal tolerance. As V F said, ambient temperature affects everything! The effectiveness of a given cooling solution when comparing is not the temperature itself, but the Delta (difference) between the ambient temperature and the CPU.