Hi womba,
I have read this post and your bug report post and I am not sure that this is the result of any bug (either with the plugin or MusicBee), but more needing information on how MusicBee works with album art.
Since renaming the songs solved your issue, it may be that all you needed to do was rescan the files:
MusicBee menu > Tools > Advanced > Rescan All FilesBut have a look at
this wiki section.
This describes the settings in:
Preferences > Tags (1) The 'Artwork' section sets up how art is stored and displayed. To change display priorities press the 'Edit List' button and at the bottom of this edit list window there is a 'Rescan Artwork' button which should be run after you make any changes.
Also note that MusicBee will store a cache of album artwork (in order to improve speed when displaying views with a lot of artwork). This can be reset by using:
MusicBee menu > Tools > Advanced > Reset Artwork CacheThis will essentially delete the existing cache, refetch the artwork from file and rebuild the cache.
In order not to clog up this plugin topic, if you have any other questions on this I would suggest you start a new post in Questions and include a screenshot of your MusicBee window so that we can see which images you are referring to.