I have recorded several movies within Channels. They appear to be in the proper directory on my Mac, but don't show up as options to watch in my Channels app. For instance, in this screenshot:

"Frosty" shows up as an option to watch in Channels, but the following three films do not. If I open the folders shown, the movie files are there. If I click on the files, I can watch them. I just can't get them to appear in Channels.
I have tried rebuilding my directory; that did not help.
Any ideas?