Appointment attendee adds re-sends appt to all attendees

A Group of users (possibly more, but this group is vocal about it) are having problems with appointment edits in GW 2014. They create an initial appointment and later need to edit the appointment to add new people. Existing users are being notified of new users added to the appointment. No time change or location change has occurred – only new users added to the appointment.

To Create Appointment: They create the appointment and send to select users
To Edit the Appointment later: They right-click (or double-click) the appointment on the calendar, select edit, and add more people. Then they press Send.

Observation: No dialog-box option is given to send only to new users. User presses Send and appointment is just Sent.

Result: Original users are sent another email regarding the appointment. New users are sent an appointment request to accept or decline.

GW2014 no revision (Linux SLES 11)
Mailbox/Library Maintenance on all user mailboxes in question: Structure; Content/Fix Problems (Databases=User/Resources