Ty for the advice. I've overclocked both my cards to 900mHz and the shaders sucessfully unlocked on one using the MSI modified bios. I'm up to 792Mhps... I need to work on my case cooling though for more I think.

I just have to say I'm loving your miner!  I've just really started getting into mining and after switching to your pool it's been a lot easier to "play" with settings. TY!

I'm using dual 6950s and getting 740mhps. I'm hoping to increase that to 840 as i mess around with tweaks.     Any advice is welcome.