Progress IndicationI IE in CONNECT for 5ess

Hello,
We upgraded firmware on our AudioCodes Mediant3000 gw connected with Asterisk via Digium boards and started to receive warnings and disconnects on wrong information element in Connect message from Asterisk. AC said that Progress Indication is allowed only if connect is send from Network side, but our Asterisk is User side and it sends it too. I checked libpri, all versions send Progress Indicator on Connect despite user/network direction.
Is is really violates 5ESS standard? Fix could be simple, but will it be correct?

Thanks in advance,
Alexander

sorry, but may be i have to post it to some other forum?