When a user is on line one and they recieve a intercom call to that set it will not display or change lcd on set. If the caller hangs up and calls again when the user is still on line one then it will display and let user know who is calling.I have tested this on different releases of Northstar and it seems to work the same way ever time. First call no display change but 2,3,4,5th call will change lcd display..any ideas or is this the way the system is built...