Problem: Answer signal not propagating via IAX2


I have a small farm of Asterisk boxes. Some are 1.4.39 and the rest is

I have problems getting the 1.4s getting notice that a call routed through a 1.8 box
was answered by the remote party.

Box 1 calls box 2 with this command: Dial(IAX2/box2/number,90,og)
Box 2 calls box 3 with thsi command: Dial(IAX2/box3/number;90.og)
Box 3 then dials via IP to an exernal provider Dial(SIP/external/number,90,og)

In Box 3 logs, external provider aswered call. Box 2 takes notice of the answer
signal 2 out of 3 times… the other time does not ack it in its logs.
Box 1 also picks up the answer signal 2 out of 3 times.

End result, a customer starts talking and 90 seconds or less later the call gets hungup by box 1
because it never gets the aswered signal.

Please help I have a lot of angry women working on commissions