I'm running dd-wrt nokaid 07-22-09 on a Linksys WRT54GS and I saw several UDP packets from the Voipo servers to ports 5060 and 5061 being dropped. I forwarded these ports to my PAP2T and that solved all of my problems. I think that the default for dd-wrt is to close UDP connections after 120 seconds to prevent the number of connections which I have at 4096 from overflowing. I see no drawback of forwarding those two ports as it avoids this issue completely. The only possible drawback is that it allows any connections to hit the ATA not just ones from Voipo so it puts more security risk on the ATA.