cover art movie.jpg not shown in MediaPalyer

Hi there,

hope someone can help me show cover art for my movies.
Some movies are shown correct, other´s dont!

Got all my movies on my NAS in folder structure, first folder “movies” and then for every movie a subfolder called like the movie e.g. Inception
In this folders are files like e.g. Inception.avi, Inception.jpg, Inception.nfo, Inception.tbn, Inception-fanart.jpg (got the files from EmberMedia Manager and works great with XBMC).

The problem is som movies are schown the correct jpg to the movie, some show the fanart.jpg and some show a picture that is wether the movie.jpg nor the movie-fanart.jpg.

Metadata fetching is disabled in the MediaPlayer settings.

It also doesn´t matter if the movie file is avi or mpg.
I´ve cleared all metadata, tried to reload metadata on specific files but it will not fetch my stored jpg.

On some movies the shown jpg in media player looks like a preview picture of the movie.

I have also checked the metadata of the movie files if there is another title or something, everything is fine…

Can somebody help?

Thanks in advance,