chevrolux: I agree that this magical 'y cable' should be included for your $390.
That is assuming of course that the device has a Telepermit/ChorusPermit for connectivity to the PSTN. I have no idea if this is the case or not since I don't have the PTC number and I'm not going to go through the Telepermit website looking for it. DSL, VoIP and FXO connectivity all require different testing, and as I speculated above maybe they didn't submit this for approval.