Vista Movie Maker

Have installed the Vista Ultimate RTM. I see that Movie Maker should be able
to import dvr-ms files (the format produced by Media Center for recorded tv).

Whenever I try, the import succeeds (I can play the file in the preview
window) however any actions such as dragging the thumbnail to the timeline
cause Movie Maker to close down.

Am running Vista on a brand new Dell laptop, Core Duo with 2Gb RAM and loads
of hard drive space...

Any suggestions as to where to look for a solution would be much appreciated!

PS - the sample videos in Vista are also DVR-MS format and they work in
Movie Maker!