When you try to quote a GB post, the browser request and URL like this: http://hikarujm.minitokyo.net/thread/7757/compose/?quote=546431
It's like it's requesting a forum thread named as the user id, I find out that it works if you remove the 'thread/7757/' part, I mean, leave the URL like http://hikarujm.minitokyo.net/compose/?quote=546431