Btw you can push that rate 3% higher by just modding a single file in the miner directory, if you are using poclbm.
Go to kernel.cl & edit
#define Ma(x, y, z) amd_bytealign((y), (x | z), (z & x))
to
#define Ma(x, y, z) amd_bytealign( (z^x), (y), (x) )
Found it on the forum some time ago. Prob. integrated in some newest miners already, but worth a try.