"Unknown CPU" and "CPU over temp." on ASUS P5E Deluxe

Hi there..

I have this problem with my new system I just assembled:

When booting, all seems fine, but then it states "Unknown CPU - Uptage to get full power" and after that "CPU over temperature error" and a couple of beeps. I get option to press F1 to continue, but nothing happens when I press F1?

The BIOS beeps this when the error is shown: 3 quick short beeps, then 4 short beeps a little slower..

I've tried to get in to the BIOS to update - but was unsuccessful - both trying "Alt"+F2 and pressing "Del" as it says in the manual.

System Spec:
ASUS P5E Deluxe
Intel Core 2 Duo E8400
8 GB DDR2 1066 MHz Kingston HyperX
GeForce 9600GT
640 GB Western Digital

OS:
None installed yet

Hope someone can help me out..

Greetings...

[Edit]
I tried resetting the CMOS following the instructions in the manual,
now I got rid of the "CPU over temperature error" but is still stock with "Unknown CPU - Uptage to get full power" and a newcomer: "CMOS checksum bad" Still getting the option for "Press F1 to Run SETUP" and "F2 to load default values and continue" But nothing happens when I push one of the to bottons..