GA-z68mx wont start with monitor attached

[nrk112]

Well, I have the problem leaving well enough alone and I updated the bios on my htpc to the new uefi u1c version. I thought it was messed up because I couldn't get it to boot afterwards. It turns out it will not boot if a monitor is attached to the video card. I must turn it on with the monitor unplugged and right after it starts loading windows I can plug it in and its fine. I CAN leave a monitor plugged into the onboard video out, but that's not what I want. Does anyone know of a setting in the new bios that might cause this? Its hard to troubleshoot since I cant get into bios with the monitor plugged in.Thanks for any help!

Specs:
Mobo: GA-z68MX-UD2H-B3
Bios: U1C
CPU: i5-2400
VGA: Sapphire 7850
Mem: 8gig Corsair Vengeance 1600

[wazza300]

yes are you setting first initial display device as the graphic card? it might be labeled as pci-e#1 or peg,try disabling onboard graphics too,if it messes up and you get no display at all you can always clear the cmos,this will reset the bios to default settings