Hi there ... ;)
Please think about that in new versions: order the thumbs / ascending or descending / differently for each album.
We could add a dropdown box to the album properties with the same options as the config option http://documentation.coppermine-gallery.net/en/configuration.htm#admin_thumbnail_default_sortorder
The default value should be "as set in config". If the admin sets a different value, it will be used instead.
Not sure if this will interfere/overwrite the current cookie approach.
If this box will be in every album differently i think that will be great. Lets try ...