@peregrine is right.
Please look here: http://vanillaforums.org/discussion/comment/174728
What actually happens is: jsConnect overwrites the avatar each time you login. If you do not provide an avatar link, it deletes the link to it. By making the changes I mention in my post, you prevent Vanilla from modifying your avatar picture at login.
No, it's forem: https://github.com/radar/forem
Ok, I uploaded a new version.
Are you aware of the libraries for this? When I was advising you, I just assumed that you were using one of them:
http://vanillaforums.com/blog/help/implementing-jsconnect-single-signon-on/
Are you sure, the parameters aren't included? Because they actually should be. Do you have a link for me to see for myself?