@Dirk, what are you doing with these thumbs? How are you using it?
if thumbgen has created the 0001.jpg, the .tgmd and the nfo file. (the jpg is already enough,
but for future change of the template the other two`s are easier and faster).
you can go to "browser"
and select the folder where you stored your movies (for this to work each movie needs his own folder)
in this folder the pohd sees the first jpg and shows it in the preview window under the "all" tab.
but if you select the "video" tab (with the preview in setup on) it shows the jpg there in
the preview window as well.
if you then press the "slow" button on your remote,
it makes the 0001.jpg full screen.
normally if you then press the play button it was able to play the movie.
but in r3875 firmware something does not owrk right as there it does not,
or it shows the movie in that folder which you at the moment are in.
but in r3643 it does work (even under the "all" tab).
just try and have fun with it.