Well, me again . I think you will be sick and tired of me by now... :)

I have been having this strange problem for a while, but because I wasn't too fussed about it I never bothered asking. I have an Elastix Box (Ver 2.3.0) on which I now have 3 VfX lines. (Getting more and more! )

The problem is that, although all can receive calls, only one can make calls. I use the same settings in all of them, but only my oldest number 9950xxx2 is able to make calls.
I have port 5060 forwarded to my machine (yes I am running IPTABLES with Fail2Ban). I juggle the outgoing routes to force calls out of the other channels and I always get "all circuits are busy" . As soon as I try changing the port from 5060 to 5061 in the trunk settings, it tries to connect for a while but then fails again. 
So upon running 3 vfx lines on the same machine, do I need each line to be forwarded to a separate port? (and maybe I am not forwarding correctly)? Or what other reason could make 1 line able to make calls and the other two not, when they have EXACTLY the same settings?

Here are the settings that work

username=user
type=peer
secret=pass
regseconds=180
registertimeout=20
port=5060
host=pan.wxnz.net
dtmfmode=rfc2833
disallow=all
allow=g729&ulaw&alaw
User context : 9950xxxx

username=usr
type=peer
secret=pass
nat=no
insecure=invite,port
host=pan.wxnz.net
fromuser=9950xxxx
context=from-trunk
canreinvite=no