I have a MICS 7.0 with PRI, using an ATA for the fax. The fax is dialing out ok and connects, but it will not communicate with the fax on the other end. The error message on the fax machine says "Remote Fax error". I tried calling using the handset and I get fax tone and handshake, so I know it's calling ok, it's just a fax protocol or something that needs adjusting-if possible. Any ideas how this can work?