Answer
The error occurs because of background noise on the modem connection, which triggers communication errors. These errors are detected and recognized by the 7TCML driver, which issues a general protection fault only if the errors occur during scans of historical data. The problem is remedied with the an updated IGSS system file called POLLED.DLL, which resides in the [Install path]\ GSS sub-folder. The updated POLLED.DLL file can be obtained by downloading and installing system Update 4.