MS Word 2000 corrupt file disappeared

I searched the forums here for an answer to my question, but did not find the same problem.

I was editing a previously saved document on Word 2000. The original doc had been created and saved on Word 2003, and possibly Word 2007 (not sure if that matters - I am not the original author) Anyway, I had saved it successfully to my jump drive, and was attempting to save the final version of the doc when I received a dialog box saying something like "unable to save...invalid file path/name" and something about corruption. I figured it was just a glitch, so I clicked OK thinking I would get it saved on attempt 2. Instead, the file was immediately closed, and has since seemingly been completely lost. It is no longer in the directory it had been stored in, and it's not in the autosave folder, or stored as a .tmp. I looked for it using some app I found online that recovers files, but it did not find it either. It's as if it never existed.

Anyone heard of this before? Can I recover the file? Thanks!