black screen after flashing bios

[pacmanpc]

Hi i have just flashed the bios on my Gigabyte GA-M57SLI-S4 m/b with bios F11 it seemed to go fine. I used the bootable cd method of doing it but when the pc rebooted all i get is a black screen with a cursor flashing in the top left. it starts the normal post process but does nothing after listing the devices.
I try to get into the cmos by hitting delete when it boots and it says entering setup but it just goes to the same black screen. If i hit the END key to go into q/flash all that comes up is a box saying POST ERROR and tells me i need to select a profile either default or last success. Both take me to the black screen again.
I have tried removing the battery for a hour or so as well as shorting the cmos clear pins to no avail.

Edit looks like i may have updated with bios for revision 1.1 of the board when mine is 1.0

Any help on this would be appreciated
thanks