I have check with STA Tech Support and they have not had anybody report this issuue with calls disconnecting. They did say that they are looking for the CO's to be between 28-35 Ma. Did you ever get a reading on the CO lines at the job site? Also, How is AT&T delivering the ciruit to your system? Is it some type of VoIP circuit that is being converted on site to an analog CO, or does the line come directly from the CO as analog?
