Change username user in ww.wp.xz.cn

Hello,

I didn’t know if I’m in right place, but I notice that I can’t login in ww.wp.xz.cn forums in Firefox because my username contain and Uppercase characters, and when I try to type it, it became lowercase automatically.

So I’m asking if it is possible to change de username or maybe anyone already had similar problem with Firefox?

Yes, I already cleaned the browser cache, etc.