Cpu Overheating?

Hi Guys, I seem to be having a intermittent CPU overheating Problem. Today it has happened twice.

**I just had the BSOD and my pc rebooted as I was writing this post!

Ok the overheating Problem 1st happen when my old PSU died in January and the Pc Guy replaced it. He reported that he had a CPU overheat on the post screen then he let it cool and all was ok.

The next time I noticed it happen was about a month ago when I brought new Ram and in the Bios it reported the CPU Overheat. It kept happening in the Bios. I let it cool and all was good and basically forgot about it till today. I Booted my pc up this morning and it froze on boot up...I reset and then it said on the post screen the cpu was overheating. I let it cool and all was good. I reset my Pc again this afternoon and got the same message on the post screen. Let it cool again.

According to real Cpu Temp at idle my Cpu Cores are all under 60c.

Any Ideas why this is happening?

**Edit I just used Real Cpu Temp load Tester and within a minute 3 CPU Cores were all at 98c. Is that Normal?

My PC Specs:

Motherboard : Asus P8Z68-V LE
CPU : Intel i7-2600k @3.4 GHz
Memory : 2 x 8 GB GB Corsair Vengence 1600mhz DDR3
Video Card : Nvidia 8800 GT
PSU : Cooler Master Extreme 2 625 watts
Case : Antec 900
Operating System : Win7 64bit
Hardrive : 1 TB Western Digital Caviar Green

Cheers

Uly