You might want to try running it in Virtual PC/XP mode. I don't think that game uses any 3D acceleration, so it should work fine that way.
I didn't realize this was an issue with Vista and 7 though. I know of two or three other games that require you to disable Direct3D acceleration to work properly, but it seems that you can no longer do this in dxdiag.
Is this series any good, by the way? I played the first Journeyman Project last summer through Windows 3.1 in Dosbox. The plot premise was very cool, but the story wasn't developed well at all and it ultimately didn't feel like much of a game.