Here's a random thought... Most home phone wiring will actually support 2 phones. I was having problems using my Rio/HPNA "on top" of my main phone line, so I just physically switched the wiring used by the HPNA to my unused "second line" of my phone wiring. An easy way to do this is to buy two second line converters (i think i've seen them in the phone section of places like Office Max)... this will work if you second line has been hooked up to the phone jacks. Most newer homes I believe do this.
Alternatively, you could pull the wall plate off and switch the wires to the second line yourself.

Hope this makes sense,
-j