Hi,

just a post for people who run into the same problem:

I had the problem, that the settings for "Photo properties" in the "Display" tab in "Configuration" -> "Options" were not stored. When I changed them, I got the message, that the changes were saved and an error message, about an error in line 360 of the admin/configuration.php that told me, the deserialization did not work.

So I looked at the database and found a string with a lot of slashes.

The problem was: In line 171 in the admin/configuration.php the values are stored with slashes ("addslashes(...)") in line 360 of the same file, no slashes are expected (and neither are they in the picture view.)
So I changed the line from:

      $_POST['picture_informations'] = addslashes(serialize($_POST['picture_informations']));

to:

      $_POST['picture_informations'] = serialize($_POST['picture_informations']);

And everything works now.

I'm not sure if the addslashes was necessary in the first place. But be careful with this.