Performa 6400/6360 & GeoPort Modem: Data/Fax Arbitration

I cannot get the data/fax arbitration to work correctly on a Macintosh Performa 6400 or 6360 with a GeoPort modem. What should I do?
This should suffice to allow the computer to automatically arbitrate between fax and voice calls.

Note that Megaphone must always be open for this feature to work.

If the above steps did not resolve your issue, you may have a software conflict. Please review the Tech Info Library articles listed below. They provide general guidance on how to troubleshoot extension conflicts.

Note that certain types of third-party performance enhancement utilities which modify the system at a low level can modify system performance enough that some features may not work correctly.

REFERENCES

Article 17768: "System SW Clean Restore: Macintosh Performa Computers w/CD"
Article 15926: "System 7.5: Troubleshooting Extension Conflicts"
Article 14343: "Troubleshooting Macintosh INIT Conflicts"

This article was published in the Information Alley on 31 January 1997.
Published Date: Feb 18, 2012