No matching peer found reistration

HI all!
i got a little problem.
i got an asterisknow pc .
i connect with my laptop to the server for set up via fire fox.
i added new user
sip is clicked
saved it
added my sip account
saved it.
an allways when i connect with an software phone to asterisknow he says
[date hour] Notice[2273]: chan_sip.c:14354 handle_request_register: registration from ´sip:user@´ failed for ´´ - No matchin peer found.

the calling rules

there where it says call using the is all six line says invalid trunk.
do i need any calling rule?

the pc software phone says this from the log file:
14:47:40 Express Talk Run
14:47:40 SIP Private IP is:
14:47:40 SIP Public IP is:
14:47:40 SIP Number: user@
14:47:40 Attempting to register sip:user@
14:47:40 Register attempt for sip:user@ failed
14:47:40 404 Not found
14:57:40 Register attempt for sip:user@ failed
14:57:40 404 Not found

can any one help me ?
i would be very happy for every answer