The Vonage report I copied was form their forums, it was not me he was responding to, but the same issue.

I should have both my backup VZ actiontec and a Westell 6100 (from ebay) here in a few days, then we can resolve this. Sometime in the evening/night when I have some free time and family internet use is minimal I will try re-configuring the Actiontec to see if I can get it to work as a mostly transparent bridge with the VZ firmware (no nat, no dhcp).