Vista - Movie Maker 6.0 - publising error "missing files" but files not missing

I'm having a problem sililar to this one - Going from Movie Maker to DVD Maker - but the solution there isn't helping me.

I'm getting an error telling me that disk maker can't make my disk because my movie maker document is missing one or more files.

But my MM project is not missing any source files. No red X anywhere, perfect playback inside MM. I have checked and double-checked each source file - 5 WMV files on an external drive, and 13 stills from a different external drive. All are where they originally were, none have been renamed or altered. I have opened these projects several times since receiving the original error - each time, MM checks my source files and delivers no error - I only get errors when I try to publish either to DVD or to the hard drive.

I have some 28 clips from these 5 source files, plus the 13 stills and added transitions between all adjacent pieces. Project is about 47 minutes. I have read forum discussions of complexity-related errors in MM2.X - are those still a problem?

This is only my 2nd MM project - I spent many hours working on it as a Valentine's gift for my wife. Please help

Any ideas out there?

Update - Based on tips here - Windows Movie maker(Vista) unable to publish due to missing files.? - Yahoo! Answers - I just moved all the source files to my hard drive where the MM app lives - all source files then showed up missing, but I browsed to find them again at their new locations, and again no source files have the red X

Same result, though. No progress.