CPU temp higher than CORE temp??

Imporant components for this thread:
DFI 790FXB-M3H5
AMD Phemom II 550 BE
bios gone from 2009-03-06 to 2009-07-27 (in other words: from first bios to latest bios.)

Yesterday I updated my bios, and what happened was that for some reason my cpu got overclocked which I noticed when I booted up my pc and checked in cpuz for the new bios. It was at 3.3ghz with the multiplier raised from 15.5 to 16.5 (which I know I never did cuz the old bios didn't have multiplier), and the voltage from 1.26v to 1.5v (which I also didn't do since this is really stupid). Temps were going up to the 60's

So, I went and returned it back to stock speed and voltage. When I booted up the PC everest shows that tems are 36-36-47. Is it normal that the CPU temp is 10C higher than the 2 cores? I don't think so because they all used to be the same, and it seems that whenever temp goes up, CPU temp is always 10C higher than the 2 cores.

I have no idea why this is this way since I returned all the values to stock. What could make that the CPU temp higher than the cores temps, exactly 10C always?

I looked around for this issue in the internets and found 1 other guy with the same problem. Right after BIOS flash his cpu temp became 10C + than the CORE temps