There was a slight typo in the one from two messages ago. (For the sake of people that tend to copy/paste without reading). The ^^ might be something with the beginning of the line along the lines of regex things. Completely stabbing in the dark though.

<param name="dial-string" value="{^^:sip_invite_domain=${dialed_domain}:presence_id=${dialed_user}@${dialed_domain}}${sofia_contact(*/${dialed_user}@${dialed_domain})}"/>