i do not know about the actual question, but i wanted to tell you that a 6950 should be getting at least 350mh/s https://en.bitcoin.it/wiki/Mining_hardware_comparison i would first look to see what others are doing to get the substantially more megahash than you
I did see that other people were getting way more m/hash than me but i couldn't message them/reply to the thread because of my newb status :/