Hi Chris;
Topic says it all... for the benefit of anyone else who might have this problem.
In context: I separate the MP3s under each artist by album thus:
\{artist}\{album}\
I have one album that absolutely refused to display the CD cover image:
\Sorted_MP3s\Albums\D\Deep Forest\Bohême\Bohême.jpg
I tried reencoding/resaving the JPG, and even renamed the image to boheme.jpg (getting rid of the ê character), to no avail.
It wasn't until I renamed the folder to Boheme as well, that it showed.