Corrupt PowerPoint File

My wife created a very extensive PowerPoint presentation. She presented it, and then decided to bring it home to save (it was very good). Sadly, she MOVED it to a key drive instead of copy. This means no backup copy. When she got the drive home PowerPoint would not recognize the file. Said it was wrong type (it IS a .ppt) or corrupt.

I have all current updates in Office (SP2 and later). I am running Win XP Pro SP2, Office 2003 SP2. Is there anything that will recover a corrupt PP file?

Any ideas gratefully accepted.