Not sure this is the optimal sub-forum.. but here goes.. Right so I upgraded from an old mac pro (that had DVI outs) to a fancy 27" iMac and I love it - but I'm having trouble with getting my 720p projector (Mits HC1600) to cooperate. I have a fair amount of hardware lying around to test with, which pretty much assures me that it's an Apple software problem. Booting to Windows will likely confirm as much. So on my 27" iMac has 2 TB ports. One uses the (USB-bus enabled) dual-link MDP-Dual-Link DVI adapter for my 30", and the other port has a new Monoprice MDP-DVI adapter. That connects to a 30' DVI cable (that's worked great for years) to a DVI-HDMI adapter on the end. I thought maybe somehow the MDP can't support the long cable run, but I just climbed up with a MBP that has MDP out and a 6' DVI cable and had the same result. Here's what's weird, though: the computer 'sees' the projector just fine - even reporting the model number (HC1600) in display preferences. I can change resolutions and 'arrangements' and everything. So the both Macs know they're connecting and are outputting a signal, but the projector never receives these signals. The MDP-DVI works fine to the two LCD monitors I've tried it with. My PJ doesn't have DVI in, obviously. I might need to go back to analog, which would be very irritating (where is that VGA-Component cable....). Guess I'll be slumming, watching movies on the 27" tonight Input appreciated!