Asterisk lync gateway trunks

Dear All,
i have installed asterisk 1.6.2 and configured as gateway for the Microsoft lync server. My configuration is as follow:
First i configured the 2 folowing sip trunks
[provider]
host=y.y.y.y
type=peer
port=5060
transport=udp
insecure=invite
allow=ulaw
allow=G711Alaw
context=from-internal

[lync]
host=x.x.x.x
port=5068
insecure=invite
type=friend
dtmfmode=rfc2833
qualify=yes
transport=tcp
context=from-internal
allow=ulaw
allow=G711Alaw

Next i configure 2 outbound rules with dial paterns as follow
rule name:to-provider
dialpaterns:+.
Trunk sequence:SIP/provider

rule name:to-lync
dialpaterns:22xxxxxx
Trunk sequence:SIP/lync

The calls work from lync to outside world and from ouside world to lync. The problem is that when i answer the phone the other side phone still rings. So what i am missing here??? any help i would realy apriciated.

Finaly i fixed the problem by first correcting some routes mistakes, as i have 2 ethernet one connect to sip provider and one connected to lync. After fixing that i could answer the phone but i couldnot hear any voice. this was fixed by adding canreinvite=no to provider trunk.