Config: 2 - PAP2Ts connected to a Linksys RVS4000 then to Moto SB5120 -Comcast PAP2T #1 is connected for alarm system. In the system tab set DHCP to NO config for static IP works fine, no issues. PAP2T #2 is connect for VOIP service (VIA Talk). Set the DHCP to YES and works like a champ, no issues, registration state goes to online in a flash. The problem---- Set DHCP to NO, config for static IP and it drops registration quicker than you can count to 1. Using any static IP address does this, .5, .9 .99, .101, 151 and so on. I have the router (RVS4000) set to a limited number DHCP addresses, start at .10 and only allow 10. Even if I set the static IP in the PAP2 to a DHCP allowable IP say .12, no luck. Go to DHCP=YES bing back on line. OK now the fun part. Thought VOIP adapter bad, had VIA Talk send a new one, exact same problem. Ahhh grasshoper must be the router then... nope. I actually have 2 Linksys routers, the RVS4000 and a BEFSX41 that I swapped in and out, exact same problem. Summary. 2 identical PAP2T adapters, one will work fine with a static IP the other will not. Swapped out adapter and router, no change. Why you ask do I want to set the IP static, for port forwarding and logging into, makes my network config easy. Help kindly accepted. Thanks!!!