Hey, sorry if this post is a little old to res, but I don't use forums often so hopefully this will get read, but I have a very similar setup to you tim, I have the same CPU, CPU Heatsink + fan and the same Thermal paste, and my CPU is currently running at 74oC playing BF3 which is a little worrying, I do need to do a clean again but when I first reapplied the new thermal paste and used a can of air to clean it I was still running at higher than I expected too.. I'm wondering, could this be the heatsink?
Also, seems we may have both been using Ebuyer? ;P