I've looked at your post twice now and realize that maybe you would benefit from the following (which I used sucessfully on my system):
Solution (
http://forum.linuxmce.org/index.php?topic=12861.msg92498#msg92498) and this is quoting from that post:
"Apparently the number detection is not yet working...so asterisk thinks it is an anonymous call. In /etc/extensions.conf the second line under globals is set to no
ALLOW_SIP_ANON = no
this kicks any phone call into internal voice message that sounds exactly like a phone provider message informing the dialer that the number is not in service. If you change this to
ALLOW_SIP_ANON = yes
and the do a core restart gracefully inside of asterisk, external phone calls will now be allowed to go in to the system
Of course you are still not "home" yet as the system then tells you that pluto default voice mail does not exist and then just hangs not knowing what to do..."