Finally

[22:16:36] matt [wronka.org]/Psi.generay Finally figured out how to configure SIP on Symbian^3 based phones. Despite registering a SIP profile, the phone wouldn't recognize it as valid. The secret sauce was a SIS that needed to be installed:

http://www.developer.nokia.com/info/sw.nokia.com/id/d476061e-90ca-42e9-b3ea-1a852f3808ec/SIP_VoIP_Settings.html