Two thumbs up! My OS X 10.2.6 system had gotten corrupted -- documents created by the app I'm building were suddenly bound to an "application" that was actually a hidden system folder named "501". I could temporarily rebind an existing document to my application, but every new document was bound to the "501" folder. Of course, document icons were blank.
RebuildDesktopX has cured this problem, with the added benefit of making application launching MUCH faster than it was. I suspect this may be due to the system cache file being reduced from 2.4 MB to 188 KB. I'm also seeing newer icons on some of my favorite documents.