No. Check each extension's option for "Aux Ringer". There may be one that is set to "Y", and probably one that doesn't ring very often, but when it does, it will close the contacts for the Aux Ringer port, giving you your phantom ring issue.

Also check the same setting for each line. Could be that as well for the same reason.

Scientists say that the universe is made up of Protons, Neutron & Electrons. They forgot "Morons".
Dave. (CTUB) Canadian Techs Use Bix!