Hi,
I have the Titan working on the mac - I've written the drivers that are currently being incorporated into TheSkyX, Nebulosity and is the base for INDI's drivers.
I will talk to Craig (author of PHD and Nebulosity) have you tried OpenPHD? This is like PHD version 2 developed on Craig's great work.
I looked at adding the ATIK driver support into PHD however at the time the PHD uses 3rd party software that would not compile on my development machine. I have a few things I need todo but I may chat with the OpenPHD folks to add ATIK support into PHD on the Mac.
Kind regards,
Nick