[jitsi-users] Problem with the XMPP Service registration formular

I just encountered a problem with the XMPP Service provided by jitsi.org. When I open the registration page via JITSI -> XMPP Service I fill the formula without problems. But after clicking the Create Account button, at the place where the formular is shown the following Firefox error shows up:
The page isn't redirecting properly. Firefox has detected that the server is redirecting the request for this address in a way that will never complete. This problem can sometimes be caused by disabling or refusing to accept cookies.

It looks like that the registration processes is not completed afterwards. The username is reported as used but I can neither login using the username/password nor use the reset password function because the mail address is reported as unkown by the reset formular at https://trac.jitsi.org/reset_password ("Error The email and username must match a known account.").

System Information:
Ubuntu 13.10
Firefox 25.0
cookies allowed, third party cookies blocked
javascript enabled

Best regards,