The slideshow stop command does not work anymore, i.e. it has no effect when pressing the button.
Furthermore, the display of the button itself is really weird:
I can't replicate this - in a test album, the play/pause button works properly, and is formatted correctly. We'll need a link to an album that shows the problem.
...could this be a bug related to jAlbum application?
No. The jAlbum core doesn't produce a single line of HTML, CSS, or Javascript. It handles only project organization and image processing. It doesn't put anything on the album page.