Are you using MediaInfo.DLL ? if so, try removing it, or disabling ID3 Browse.
i have lost all my video listings in the new rr .
i used the new rr config to list my video formats(which dose not list mp4)
of which my files are and always have been , so i added mp4 to the list and the video skin freezes and won't show the video list.
i removed it, i thought the mediainfo.dll had to be in there for reading other tags, i going to asume this is a little bug then.
The problem is that it's an overzealous little guy (MediaInfo DLL) that takes forever to read info from files (and it actually does) -- so it wasn't frozen, it was just lagging like hell.. I added most video file formats to an exception list (so mediainfo doesn't slow anything down), but .MP4 is not really "common" for me since that is most likely an ASF, WMV or AVI file renamed to that.