Problem - mac -> tivo and back again

I'm having an issue with some video files and hoping someone can assist. Here's what's happened so far:

Took video file on my Mac, used VisualHub to convert to a TiVo compatible format. (mpeg)
Transferred video to TiVo using TiVoDesktop for Mac, no problem there.
Then, in order to free up some space, I wanted to take the video back off of the TiVo using the Roxio Toast program. I got the file back on the mac, now in .tivo form (and watchable via Toast).

Here's where the problem is. I have the .tivo file in the folder TiVo Desktop looks in, but my TiVo cannot see the file when I bring up my computer in the Now Playing screen. Other mpeg's are showing up, but this .tivo file is not.

Any clue why this file isn't showing up?