I strongly recommend using more than one temp monitoring program to get the best results. Two is good, three is better. When 2 or more temps are close to the same, chances are its accurate even if a third is way off.
These are the ones that I use for an i5. Maybe they can help you:
Core Temp (same as above)
CPUID HW Monitorhttp://www.cpuid.com/softwares/hwmonitor.html