Multiple Registrations
 

I have been using voxalot for a while now as an outgoing service and wanted to try something new. I have a spa2100 set up with my primary vsp engin registered on line 1 and voxalot on line 2 for outgoing calls.
What I wanted to do was register both lines to the one voxalot account and have voxalot register engin and forward all calls to both phones. I have read that Ron has this working (not nesc with engin).
I registered successfully to voxalot with both lines on one account with ports 5060 and 5061. I registered engin via voxalot successfully as well. When I have either line on voxalot with the other not registered everything works fine. However, when I register both lines I get the nice optus lady on my mobile say that this number is not in use.

Can anyone suggest where the problem is?