Thanks for the suggestion.
I switched to SDK 2.1, but left my drivers as they are. I also switched to phoenix miner within guiminer. Switching to SDK 2.1 resulted in a net increase of ~5MH, and then the switch to phoenix resulted in another increase of ~3MH (1.5 per GPU).
Now, I really don't want to go back to 10.6 since I use this machine for everything. However, in CCC, I noticed that both of my video card clocks are at around ~500 MHz even with guiminer running. Is there a way to have guiminer "trigger" an increase in clocks, much like playing a game would?
EDIT: tried some phoenix flags, but they did not work. How do I get the "phatk2" kernel to work with phoenix (within guiminer)? That is something I did not try yet