DVI Signal Splitting

I have an NVidia 8800 graphics card. The card has two DVI-I output headers. One of these connects to a Matrox TripleHead2Go digital screen extender. This works properly.

I need the other output header to connect to a flat panel monitor and to a VRInsight CDU-II flight sim computer. The monitor has a DVI-D header. The CDU has an analog (VGA) header.

I have tried numerous solutions to split the system's output signal between these two devices. I tried an electronic, powered signal splitter with no results. I tried a manual signal splitter which worked when connected to the monitor but did not work when I connected a DVI to VGA cable to the CDU.

Is there some kind of magicical solution to get a DVI signal to split to two devices?

Thanks

Frank