I have a problem with only one album:

whatever images sort configured in the admin, the images of this album are sorted by filename ascending, whatever the theme used.

I don't have this problem with all other albums.

version used : Zenphoto version 1.4.2.3 [9710]

Are there any odd characters in the title of the album?

the physical name (the folder name on my server) of the album is "photo-du-mois".
the logical name (the title of the album on zenphoto) is "photo du mois".

this album is unpublished.

hi

any idea about my issue ?

Well, with no information to go on, no hypothesis can be made. Only one album? What is unique about that album and its images? I suppose you have carefully checked your logs for errors, etc.

hi

in fact, reneesanguinetti has found the issue (http://www.zenphoto.org/support/topic.php?id=11016).
in my case, my unsorted album was with a random thumbnail.
If I set a fixed thumbnail, or choosen the most recent, my manuel sorting is set in the gallery.

I will have a look on the ticket http://www.zenphoto.org/trac/changeset/10137 and will test it as soon as possible.