I'm trying to find the best config settings for cgminer on Mac OS X.  It runs just fine, but I'm only getting about 30kh/s with the scrypt settings I'm using.  That's less than I get CPU mining on the same machine.  If I switch to Bitcoin mining on the GPU, I get about 70 Mh/s.  

Specs:
AMD Radeon HD 6750M
MacBook Pro 2.2 Ghz Core i7 cpu
OS X (10.8 - Mountain Lion)

I know this isn't the most efficient use of my time or hardware, but my electricity is free and I have access to a lab with 30 of these machines every night, and the laptops are replaced every six months anyway so I'm not worried about killing them.  

Any thoughts?