That's why I've been telling people to use speedfan for everyday Wolfdale temp monitoring. core temp & real temp are good for overclocking.
Heh.. Any of those programs are fine, as long as you know the Tjmax, which simply, nobody really knows.
If the Tcase looks about right, I'd go by that temp. As long as its stays below the max load temp for Thermal spec's that Intel does publish.
Although, if the Tcase sensor is screwing up... I'd just RMA it.
But this guy... lapped it.