Having played with this stuff for a very long time, I decided to do some forced reboots and registration.
1. I rebooted the voipo adapter. That didn't seem to do much. Many inbound calls still rang, but dead air when I answered. Outbound no problems.
2. I rebooted my router. Same as #1. Inbound calls were still hit or miss as far as connecting or getting dead air. Outbound still never been a problem.
3. I then logged into vpanel and in beta, assigned my virtual number to port 2 of the adapter. Rebooted adapter and forced server to re-register. I then changed it back to primary number; rebooted and forced the server to re-register. Finally, did it a 3rd time and assigned the virtual number to port 2 of the adapter; rebooted, and forced the server to re-register.

I've only experimented with 3 inbound calls. 1 from a POTS line and 2 from 2 separate cell phones. So far, ALL 3 inbound calls worked fine. No more dead air. I'll monitor for the next few days to see how it goes. Also, FWIW, I don't use QOS, Port Forwarding, or DMZ on my router. I have 30mb down and 5mb up internet, so QOS isn't an issue.

For those who don't have a virtual number to play with and force re-registration; I'm sure you all have failover established. Probably to your cell phone. Simply unplug the power to the voip adapter and LEAVE it unplugged. It will take a few minutes, but the servers will go to failover and forward calls to your cell or wherever you told it to. When you know your inbound calls are in fact being "Failedover" (If that's a word); simply plug back in your voip adapter and allow the voipo server to re-register with the adapter. See if this helps. Like I said, I'm simply experimenting, and I figured it couldn't hurt to force my account to be rebooted. No promises, but so far, (3 calls), mine is working better. I'll comment tomorrow to say if I got any more dead air inbound calls. later... mike...