Vigor 2710 Caller ID PSTN and Relays

I am trying to understand how the relay within the Vigor 2710 ADSL Modem works.

I've got a Skype Freetalk adaptor, which works fine, however, when I plug it into the Vigor 2710 as shown in the picture below, I get the following:

• PSTN calls don't ring on Phone 1 or Phone 2
• Skype calls do ring on Phone 2
• The Caller ID on inbound Skype calls shows up on Phone 2, but the call is not logged in the modem

The Relay is used to switch voice calls to/from the PSTN or the Voip feature within the heart of the modem.

Call Logging (or not)

The modem has some features associated with a relay, but it is not clear how the relay is connected / how it is controlled.  There is a command line option in the modem:

> voip dsp relaydbounce off
> voip dsp relaydbounce   
% voip dsp relaydbounce [on|off]
% on : Enable relay filter noise but it maybe ignore the caller-id!!!
% off: Disable relay filter noise. But the noise will cause the relay to switch to PSTN!!!

I've tried both options for the command, and neither allow the incoming numbers to be logged.

Phone Not Ringing

This one is also strange:

• If I plug the phone handset directly into the Freetalk box, it rings for incoming.
• If I plug the PSTN line directly into the 2710 modem, the phones connected to it ring for incoming.

So it suggests that the problem is a combination of the Freetalk box and the modem, but I understand not!

Help

I suspect that an understanding of how the relay is configured in the 2710 modem will help the overall understanding - any help would be greatly appreciated.