well... I have the same problem. Now I have a solution.
Ok, ok, ok... maybe it's not a great solution, but it's work and I'm playing right now.
I install Virtual PC from Connectix, you can download a trial from http://www.connectix.com/
I create a DOS machine and I can use my games now.
Here's the solution. Go to http://f0dder.has.it/ and click Misc. Download the thing and unzip to your UFO dir. It creates a folder called xcom, here are the files you need. Move them in the UFO root. Start the game via the new loader, voila fixed.