I just upgraded from JAlbum 12.7.2 to 14.1 and am re-generating my albums to use the Tiger skin. I found an issue if the same image filename exists in multiple directories, even though the image itself is different. In these cases, the folder thumbnail that is used is duplicated on each of the different folders. I assume there must be some caching going on using the filename as the hash key, but this will not work correctly if the same filename exists in multiple directories as is my case.
I did not have this problem using version 12.7.2.
Thanks again for all the work, and I am really liking what I see so far with the Tiger skin and new functionality.