Hello- I feel a bit like an interloper here. I don't own a Mac. But many of the Professors our Dept. at the University I work at do have them. Mostly Powerbook I think. I also know this is a real long shot but here's the problem: Profs come in to one of about 80 rooms and display their laptops on data projectors. Seldom is there a problem there. But several of them have trouble getting audio to play when they insert the 3.5mm stereo plug we provide into the Mac's headphone jack. It's not that the mac doesn't play the sound- just that the contact between the plug (male) that we provide and the (female) headphone jack seems a bit dicey. We've replaced the cable/male connector 3 or 4 times and no-one with a PC has ever reported this problem. Our test equipment has no problem. It just seems to be Macs which appear to have just the tiniest bit of "play" in the headphone jack. Have any of you Mac users experienced anything like this when plugging anything into the headphone jack? There'd be no contact or scratchy contact. If so, does Apple use a non-standard 3.5mm plug? Any insight woudl be welcome! Thanks.