Windows 7 CMOS settings failed - motherboard (& BIOS)

If you have followed you motherboard documentation regarding resetting the BIOS, as well as, as you have suggested, removing all external power sources from the motherboard and removing the battery for 10 minutes or so, then my only guess would be that something may have corrupted the BIOS chip, a failed firmware flash, or an electrical mishap like a spike or short.
Is this a new build? Has it ever worked? I assume you have already disconnected any USB cables from all USB ports on the board? Can you provide some specifics as to Manufacturer Name, Model Name and Number, Revision Number, etc., for the board you are using, it's possible someone might have some specific experience with the same or similar product. Other than that it may be RMA time if that option is available to you.
Good luck and keep us posted
Regards
Randy

Battery was out just for about 10 seconds.

ASUS / P5B / intel P965 express chipset (what is FSB 1333?)

How do you mean 'a new build'? Computer is about 4 years old.

Good work and well done. Thanks for posting back and updating your thread with the followup information.
Much appreciated.
Randy