I've created a trac bug for this as well, and am posting it here in case anyone else has seen this and found a more practical solution.
If you want to look at it in trac, it's #1381
I have a gallery, containing 4 or 5 albums. Recently, sort-order breaks in one of the albums (which contains around 260 images) when new image batches are uploaded via the UI.
Sort order is set as Date(Descending), but after uploading a large group of new images, becomes 'stuck' - I don't know whether it's internally using date ascending or ID ascending, but changing the sort order on the album to any value has no effect.
If the newly-uploaded photos are deleted from the gallery using SSH, then the sort order returns to Date(Descending).
First time this happened, the photos were all named .jpg, and changing this to Picture_.jpg on the server seemed to fix the problem.
Second time, with about 25 files all named dsc_.jpg, the same thing has happened.
This time moving the photos away, and moving them back in batches of 5 or so seems to have fixed the problem -- at least for now.
zenphoto/installation details are:
Zenphoto version 1.2.8 [4881] (Official Build)
Current gallery theme: default
PHP version: 5.2.8
Graphics support: PHP GD library bundled (2.0.34 compatible)
PHP memory limit: 96M (Note: Your server might allocate less!)
MySQL version: 5.0.86
-PJC
To reduce redundancy, here are my answers to some questions already asked in trac:
Some questions: Does the drop-down indicator still show Date (Descending) as the sort order when this happens?
Yes
Which area are you viewing the images--the front end album, the back end image edit tab, both?
Both
For each, what is the "selection" for sort order that shows in the drop-down. Does it change?
The "selection" is Date(Descending) for both, and changes when I change it, but the "apparent" order doesn't change
Do you have any guess as to what the order actually is?
I can't tell directly, but my guess would be Date(Ascending) or ID(Ascending), which I'd guess would visibly look the same?
Have you tried refreshing pages a few times to see if the order changes?
Yes - nothing changes unless I remove and (re-)add pictures in smaller batches - 5 at a time works just fine, whether added via the UI, or copied in the SSH terminal. I haven't done much experimentation to find the threshold, but would guess it's something under 10.
It is actually not necessary to post the same on a ticket and on the forum. Therefore we will respond on the ticket and close this thread. If anyone else encounters similiar issues please also comment on the ticket directly. (http://www.zenphoto.org/trac/ticket/1381).