(Thread moved to Plain forum section.)

In the jAlbum Explore view, right-click one of those thumbnails and choose Extensions > List metadata. The original file name probably got picked up somewhere along the line, and was written out to the xmp.dc:title metadata field. So now, jAlbum is still picking it up as the title.

These kinds of things are tough to untangle. If you entered a new jAlbum title for each image, that would replace the one that's been stored. Alternatively, you could use another app to correct the xmp field. Either way, it's laborious. Easier just to tell Plain to display the Base name instead of the Title in the captions.