Gigabyte Z77 UDH5 Crashing At Idle?

I've a bew Gigabyte z77 UDH5. I've been having odd shut downs/crashes when I've left my computer for long periods of time at idle. I've heard this may be a problem with this MB. The odd thing about these crashes is the computer completely shuts down.

Anyone else having problems? Does the new bios upgrade fix the issue?

Thanks