More than likely. On GSWave in settings -> Account, under Netwrok Settings make sure that the Outbound Proxy has your SIP port correctly set. E.g. test.me.co.uk:5060.Is this related to changing the ports ??????
Also remember that if your SIP server name resolves to your external public IP address then it will not work if you are trying to connect from a device on your internal LAN to which your public IP is Natted. Very few routers will let you "double NAT" I.E. go out and back in again. I hope that makes sense.