Sipgate / C475IP/ TG585v7 problems

I have sipgate account, new Tg585v7 from BE with a static ip and the C475IP.
have spent weeks port forwarding, disabling stun etc etc .
Nothing seems to help.
At the moment I think I can make calls all the time ( touch wood)
I recieve calls intermittently.
Anyone have any ides.
Sipgate cant think of anything more, thomson said upgrade firmware and BE said not our problem .

Help !!!!!!!!!

vinces1969