Hmmm... sounds like the info from the "iMovie Library" in the Movies folder (I didn't know it created one, but I should've expected it; similar behavior to iPhoto and iTunes to have its own "library folder"); as such, that's just a collection of files, and not just one specific exported file.
In order to try this myself, to get an individual file/movie as the output, I had to be in iMovie (specifically on the Library tab of the window), go to the File menu -> Share -> "File...", give it some info about the movie, click "Next...", then give the file a name and choose where to write it (sounds like you used the Desktop; I tend to follow the default folders and used my Movies folder).
When that finally completed, I went out to the Finder, opened a new window, selected the Movies folder in the sidebar, located the file, selected it, and did a "Command-I" ("Get Info") on the movie file itself. Based on how I had it set up, under "General" it reported "Kind: MPEG-4 movie"; under "More Info", it reported:
Codecs: AAC, H.264
Color profile: HD (1-1-1)
Audio channels: 2
So, to make a long story short ("too late!"),... when you were in iMovie, did you use the File menu -> Share -> "File..." method to write your movie to a standalone file,... or did you just track down your "iMovie Library" and try to bring that into Toast? If the latter, I'm guessing that Toast has no clue how the "iMovie Library" is organized (and doesn't care, either); you probably have to "share" an individual movie to a file and then try to bring that into Toast.