I received my card yesterday from Newegg and unfortunately it cannot unlock the extra shaders. I'm slightly disappointed, but at least it seems to overclock very well, and in the end the extra shaders are only a 3% to 5% difference.
I was getting artifacting within a few minutes of BC2 until I set my clock speed back to the default 875 (as Nibathy noted, it is set to 900 by default now). Also note the memory scaled back to 1250 (default is 1300).
No GSOD as of yet, but it is still early.
Why are you so adamant that this fix is universal?
Nobody seems to have a good idea of what is causing GSOD, including AMD/ATI.
It's great you found a solution that works for your system, but it's not going to fix everyone's issues (it didn't work for me either).
Been having the same issues on my XFX 5870 as well (same model number, ordered from TigerDirect).
I went ahead and updated my BIOS with the USB link you posted. Will give Bad Company 2 some time later to see if my GSOD issues have been resolved.
Bios Information from CCC, before and after...