Benjamin: The Digital Cinema Desktop is a Final Cut feature, even if implemented as a Quicktime Video out component. As you can see (by the lack of options) is not really meant to be invoked from other applications which use standard Quicktime video out for external previews. That requires a device with a proper QT video out driver. You could use an inexpensive device, like a Blackmagic Intensity with an HDMI to DVI cable, to feed the second display.
Or you could just ask AE to play RAM previews at full screen, in which case you don't need to enable video previews at all. Together with the ability to take into account a calibrated display's profile, this should make for very high quality previewing on computer monitors.
If I am following you correctly (which i might not be) you are saying that the reason this is working on other systems in the company and worked on this system before the reinstall is just a lucky break? And AE is not meant to have the Digital Cinema Desktop preview at all?
thanks again for the help and insight.
I am only saying that Digital Cinema Desktop is a Final Cut Studio feature, designed to work with Final Cut Studio applications. In fact, if you don't have FCS installed, the option won't be listed as one of the QT video out options.
I didn't say that it was a lucky shot. Just that it wasn't designed by Apple to work with non-FCS applications. It appears listed because it uses the same framework used by video out hardware. "Your mileage may vary", in other words. I undertand it's also limited to some display resolutions.