Q6600 and version 99.5.27 temperature change

[stalkingturkey]

I'm not sure if this could be considered a bug, but it has been bothering me. I recently updated my Coretemp version from version 95 to 99.5.27, and my temperatures changed dramatically. In version 95, the average temperatures for all 4 of my cores (Q6600, OC to 3.4, B3 stepping) was between 42C and 49C, and now, when I updated, it dropped almost 10 degrees, with temps averaging between 30C and 36C. My cpu temp through Nvidia monitor as well as through the BIOS (MSI P6N diamond, Nvidia 680 chipset), has consistently stayed at around 21C. So the question is, which one of these is the accurate temperature?

Thank you

[The Coolest]

The TjMax value for the B3 stepping Conroe/Kentsfield was adjusted to 85C (it was 100C previously), so you will see an immediate 15C drop in temps between the two versions.
I would say if mobo reports a temp around 20C then 30-35c for the core temps looks pretty accurate to me.