MeThinks the WS467 is not a 3-way switch. You would need a WS477 which has an extra lead on it called the travler wire. That should work with the PCW03 that you have.
(http://www.bdshost.com/X10/lpup.gif)---(http://www.bdshost.com/X10/lpup.gif)---(http://www.bdshost.com/X10/lpup.gif)---(http://www.bdshost.com/X10/lpup.gif)---(http://www.bdshost.com/X10/lpup.gif)----KDR