Like what problems?
I'm not to familiar with DX11, cause I'm still maxing Crysis DX10 lol.
But just explain your problems, I mean if the card is fine its mostly likley a driver issue.
Not actually man Drivers is fine, i google'd around and found
out that dxdiag says im running Dx11 but my 5850 supports upto 10.1 only
and i found out that there is a hotfix for it that resolves the issue i just downloaded it now
but i must remove my drivers reboot install the hotfix to clear the error and then reinstall the drivers
and it will be cleared up, ha ha what a mission lol