I have 2 Asterisk 1.6.2 boxes with IAX2 trunk. Box A has a PRI terminated to it. Box B does not have any out side trunks.
When placing a call from box A to a outside destination all is good, however when I place a call from box B to a external destination, the call gets a false ring over the top of the person answering the phone. Calls placed from a phone on box B to a phone on box A are good, its just that last leg that produces it.
that is how I have my system setup. PBXBRG is 1.6.2.12 (contains a TE420 with 2 PRI to telco) and PBX1 is Asterisk 1.6.2.6. IAX2 connection between the two.
As voipcitadel said, post some CLI output. Will probably need it from the call on both boxes.