Whilst I'm generally really impressed with the quality and function of Gigabyte Motherboards, I've now encountered the same issue with 3 separate ones - an i5 and two i7's, running Windows or Linux.

The issue is that you shut down the computer, everything goes off.. then starts right back up again!

This appears to be a very common problem, a simple google search will come up with many hits and numerous victims of this. Nobody (that I've found) has hit on a solution yet, and suggestions usually end up with - replace the Motherboard!

This should not be necessary in my experience, as I have the solution. Read on, fair audience!

• Restart your computer (shouldn't be hard, as it is doing this all by itself!)
• Enter the BIOS by pressing DEL as the computer is booting.
• Reset to Optimal Defaults
• Ensure that the correct boot device is set for startup
• Save & exit.
• When the computer shuts downs (and inevitably starts back up) hold the power button down for a few seconds, until everything turns off again
• Remove the power or either at the computer or the wall. Turning the power supply switch to OFF will NOT do the job - you MUST disconnect the power!
• Leave for a minute or two, then reconnect the power and switch on
• A shutdown should now work correctly!

This technique has worked numerous times for me now, please let me know if it works for you!

I haven't detailed the exact steps within BIOS, as motherboards vary slightly according to the model - you'll have to go hunt for yourself.