SIPEx - Help

Hi
I try to run SIPEx in 2 devices (E61 and N95) but it doesn't work.
I configured sipphone SIP profile on 2 devices and enabling the profile from SIPEx goes well ("Profile enabled!" in LOG).

Sending an instant message does't do anything (no change in the log both for sender and receiver).

Inviting for a game gives these 2 messages:
"Response from SIP engine: 100"
"Invite declined by remote: 477"

Can anyone here tell me what the problem is?

Thank you very much