I am pretty sure that you can now successfully share credit for submissions.
When you add/edit a submission there is a new field call "Contributors" where you can add the ID
of author's that have helped you with a submission. They will get the same XP from the submission and voting that the person inputting it gets....positive or negative.
I did some minimum testing so please let me know if something errors.
This is NOT retroactive. It will start from now on. I would be happy to amend XP to contributers if you tell me which submission is updated with their IDs. PM me or respond to this post with a link to the submission with collaborators.
PS, I went through and updated the rest of the permissions on the gallery that were acting up. You should be able to add pictures to the gallery again now. And, no, I am sorry, the pictures that were previously uploaded are lost.
Another example of what it looks like: http://www.strolen.com/content.php?node=50
See the announcement
for how to add pictures.