Maybe I found the solution
This is the only VGA Bios on the website;
Version Size Date Download Here Description
F3_C 0.17 MB 2011/01/14 Asia China America Europe Europe(Russia) : FTP / Http
ATi Source BIOS Version: 013.007.000.003
ECLK/MCLK is 775/1005MHz
Release for Hynix memory
Enhanced game compatibility.
I think i've got an older bios on the card, so this might solve my problem
By the way can the shaders be unlocked on these cards with a 6870 bios?
AMD told that they are cut off by laser but I've heard a few times that there
are some cards that unlocked with 6870 bios