This probably isn't much help but when I restarted in OS9 & visited the forum I found it didn't recognise me (ie: unregistered.) Oooh that could be handy I thought, lol.
I suspect that overall the site admin is the only person with the ability to change user names properly.
I still haven't forgotten the pizza girl. lol I think Neil Young said that about Johny Rotten, Gone but not forgotten - Out of the blue & into the black (or was that out of the black & into the blue.)