I agree that it is a faulty sensor but it may be the mobo thermister sensor not the CPU internal core temp sensor - depending on which temperature HW monitor is showing you.
That being said if your 965 BE was running too hot say above 60C actual temp, it would start to cause system errors, BSOD, etc. If that isn't happening then you CPU isn't overheating.
Building a reliable PC involves more than just assembling the parts. You need to be able to configure all of the BIOS settings appropriately. This can be quite involved and frustrating as it can require a lot of trial and error with stress testing. It is however often the only means to get a 100% reliable PC.