It seems I need a Sourceforge login before I can file a bug ticket. I have a login, so it's not a huge problem for me, but I think it could easily discourage an OORexx user without a login from filing a ticket.
For not-logged-in users the Create Ticket button is missing from the Tickets screen. On trying the URL directly from a not-logged-in session, you get dumped to the Log in screen.
If there's a way to remove this restriction, I think it should be implemented.