ASUS P5B-Deluxe erroneous Tcase temp

I have been having a small issue of late with my CPU. I am running an E6600 OC'd to 3.0Ghz stock voltages with a Zalman 9500 on a P5B Deluxe. My temps at Idle are: Tcase = 32C / Tjunction 44/42 respectively. This is after some small temp corrections following CompuTronix's fantastic temp guide. Anyway, lately I will notice a temperature alarm and the Tcase will be reading 82C! Both of the Tjunction temps are still in the mid 40's.

The first time I saw this I nearly had heart failure. I whipped out my IR temp gun and the temp on the HSF heat pipes were reading low to mid 30's. This erroneous temp is being reported in both Speedfan and AsusProbe. A normal reboot corrects the problem and I might not see this for another couple of days. I am suspecting that the Tcase sensor is damaged. Any thoughts?

I believe I have 2 more months to RMA the Processor. Is it worth the hassle or would you consider this a minor inconvenience? I had planned to lap the heatsink and the CPU this weekend in an attempt to hit 3.6GHz OC stable on air, but now I am concerned and thinking that I should wait to fix my temp issue first.