I am currently working on version 2 of that mod...
All the mod does is allow you to login to 4images using your facebook account, no real gallery connection.
this mod...
http://www.4homepages.de/forum/index.php?topic=29422.0might be what you are wanting. It adds a like/send button that posts your 4image gallery thumbnail link on your facebook newsfeed. does not actually upload/download images to your facebook albums.
after I get vesion 2 of my mod running without errors, that is next on my list on things to do, if I can figure it out.
I would also like an interface to upload/download pictures between 4images and facebook.
Anyone interested in this? it may help me work harder on getting it done