I have tried a few different miners and a couple different pools but it is not working.
I have a Radeon HD 6950 card (with the extra shaders unlocked using
this method, with +20% power on)
When I start the miner it shows me my MHash/s but it is getting hardware errors and no shares are being accepted and none of them are being rejected, it is just hardware errors.
I used to mine and it was working fine (though this was a couple years ago now, but I was using the same GPU)
I have tried using GUIMiner, PheonixMiner and DiabloMiner.
I've gotten a few different errors,
"No JSON object could be decoded"
"Verification failed, check hardware! (0:0:Cayman, 38570c89)"
"IO errors - 1, tolerance 2"
I've had a look around but nothing really seemed to help.