There were some issues in earlier revisions that should now be fixed, otherwise you may not have tls support compiled in which is required for talking to googles servers.
I've just updated and same result. I fired up Google Talk on a Windows machine then added the contact I've setup on FreeSWITCH and even with mod_dingaling in debug mode I don't see the invite-request packet come in at all so it might be Google filtering those invitations and making them so that only a Google Talk client can see and act on them. Possible?
- Gonzalo