Hi there,
So, I have the same problem with you guys. My PCs are ThinkPad X200 and T410, both of them have exactly the same "0251:Stystem CMOS Checksum Bad- Default Configuration used". So that is not the problem of hardware, I guess, but the bios program. So, right now I don't dare to schedule its shut down, boot up and also WOL. It's really pity and helpless.
Wish you guys could figure it out someday!
Best regards,
Alex