I have been using Intensity Pro cards in Mac Pro's for about a year with no problems. This month I got three new "Nehalem" Mac Pro's and the problem I have is that when you boot the computer up for the first time, the card shows up fine. When you reboot it is still there. When you shut down and restart...the card is gone. Not even the system profiler shows the card. I took cards out of working systems and they show the same behavior but then work fine in their old system.