External HDD file list not refreshing

I’ve just copied a bunch of AVI’s over the network to my external drive connected via USB to my WD TV Live.

Although I can access the directory from the WD TV, none of these new files are appearing on the files list. Only older files are shown (and can be played back).

I can’t find a way to refresh the list. It should do so automatically.

I’ve upgraded to the latest firmware 1.04.17. If it matters, I copied the files from an iMac, and the drive is formatted as Mac extended (not journaled).

An update on my issue.

When I go to Videos, then USB external drive, then open my Movies folder on the drive, only one movie with cover is shown, in the default thumbnail view. This happens every time. None of the other dozen or so files are shown.

When I switch to list view, then all files are shown. When I then switch back to thumbnail movie, then all the movie covers suddenly appear, as they should.

Something appears to be wrong with reading files in the thumbnail view, when I first try to view my external drive.

If it makes a difference, each movie file has an associated cover file, in that directory.