One thing that you must change is the host setting for the trunk USER details. It needs to be the same as the PEER settings and must not be set to "dynamic".
USER details:
context=from-trunk
fromuser=094xxxxx
host=sip.gotalk.com
insecure=very
...
Depending what you have set as the "Inbound DID" for extension 505, you may also need to change your register string:
Register String:
094xxxxx:
[email protected]lk.com/505
The number on the end of the register string (after the slash) is what gotalk will send to Trixbox as the DID number of any inbound call so it needs to match the DID number of the extension you want to ring.
Try those changes and let us know if it fixes your problem.