Said By Aron SchatzBIOS updates MAY change settings. You should always go back and make sure everything is correct after an update. Put set to defaults and see if that works.
Said By Aron SchatzCMOS checksum bad means that the battery was pulled or the settings were garbled. It'll load defaults on that boot and expect you to fix them.
This is a very strange problem. Perhaps the motherboard is hanging on a component startup? Try pulling the drives to see if this cold boot problem goes away.
Do you still get that RAM warning?