With the current version of boinc, I no longer get a connection to the running boinc client by executing boinc_gui. Instead I get an error message: "The passwort you have provided is incorrect, please try again". I have configured no password, and I would not know how to do this. "-allow_remote_gui_rpc" is the only command line argument to boinc_client. Ethereal tells me that the two processes were indeed communicating over TCP port 1043. I can attach the TCP stream if that would be of any use, but it really looks like a failed authentication. boinc_gui worked in previous versions of boinc, perhaps two months ago. kboincspy gets a lot of unauthorized messages over the TCP connection as well, but emits no error message to the user. And it can display at least some information.
I found the password contained in /var/lib/boinc/gui_rpc_auth.cfg This file seems to be randomly created by boinc_client, not the ebuild. Maybe an einfo in the ebuild would help.
I agree, einfo added. Sorry about the delay - real life is really hectic at the moment.