Got my third mac pro delivered a few days ago (this time with an 8800gt) and it seems to have a fault I've not heard of before. It seemed ok for a few hours, then I decided to do an apple hardware test just to make sure. Rebooted holding the D key, and just got a black screen. Tried again, another black screen. It can still boot into OSX but it no longer recognises any DVD ROM that I put in the drive at any point. Cannot boot from install DVD by holding C key, it just boots off the hard disk. If I boot holding the option key I get a black screen, although pressing enter does then bring up OSX, so it is probably working in the background, but there is no video output until OSX finishes loading so I cannot see anything until that point. I think the hardware test is a similar story (invisible but actually there), as if I press enter I think it continues as I hear the disk start doing something. I have tried multiple PRAM zaps and SMC resets. No improvement. So all I can currently do is boot into OSX (black screen until it finishes loading) and then open and close the DVD drive without it ever seeing any DVD disk I put into it. Do other 2008 8800gt users get a black screen until the last moment when they boot into leopard? I get the impression something is preventing video output from any source until OSX finishes loading. I don't understand what it could be, or why it completely stopped recognising DVD-ROMS after the first attempt at doing a hardware test. Very strange and probably a third failure for Apple and another step towards madness for me. Any suggestions before I send it back?