For some reason on my i7 iMac I've lost the ability to play audio from Mini Displayport devices like my MacBook Pro/PS3/360 etc when they're connected. It was working up till a few days ago. Regular sound from the iMac works great. I did a fresh install on an external drive of SL 10.6.2, and audio then works fine over Displayport IN. So, clearly some files changed on 10.6.4/10.6.5, and I'm trying to find out what those files are. Anyone able to help? All help appreciated! I'd rather not have to reinstall my OS for this seemingly minor issue...!