I have followed the instructions from http://nerdvittles.com/?p=795 up until the extension 701 part - instead of editing 701, I created 2 new extensions for a spa3102 and a android sip phone app, both of them have connected to the Asterisk server and can place an outbound call (via Google voice), and the dialed number rings, but that is where things stop working - the phone that the call was initiated through keeps ringing, even after the receiver accepts the call, and even if the receiver ends the call, it still keeps ringing on the the calling phone. This occurs both via the spa3102 and the android app (uTalk)
system/version information:
Asterisk version: 1.8.8.8.0
FreePBX version: 2.9.0.9
PIAF version: 2.0.6.2
Cent OS version: 6.2
Incredible PBX version: 3.0.5
Android softphone app: uTalk version 2.4.3
SPA3102 Software version: 5.2.13(GW002) Hardware version: 1.4.5(a)
this is all on a LAN where the router has reserved the IP addresses of each of the devices
the computer running Asterisk has a AMD socket A CPU and 768 mb of ram
edit: I have solved it by following these instructions:
http://www.personal.psu.edu/wcs131/blogs/psuvoip/2010/11/adding_google_voice_to_freepbx.html