You still have two opening Body tags but I think it is something else.
I went to vBulletin's board to see if it was an issue with their software or something that you did. I don't have posting permissions on their board even after registering but I was able to do testing on the edit sig page and it is something that you did.
This page doesn't work.
http://www.greenguysboard.com/board/...editsignature#
This page works properly.
http://www.vbulletin.com/forum/profi...=editsignature
As far as I can tell whatever javascript library that needs to be loaded in order for the smilies and other javascript functions to work is not loading since none of these things work on GG&J's page but they all work properly on vBulletin's page.