Findng lost iTunes media files?

For reasons that are mysterious, sometimes a media file in iTunes will "get lost". It's still there where it always was but somehow iTunes looses the ability to find it. Support suggests Searchine your media folder for it and re connectiong it. This is a poor solution and is no solution when a number of files "get lost". Has anyone written a piece of software that can scan the media directory and reconnect the loat files? It would not be a very hard program to wite.