wake-up calls are somehow transferring to room 220. It seems like they go to the appropriate room they were set for plus then also go to room 220.

Check Command 100, Register 10, Bit C. Bet 2 things.

1. Ext 220 is the first ONS port in the system!

2. Bit C is set to 3!

Read up on automatic W/U with RAD in section 105.

I have run into this problem several times. I had a RAD connected to the first system ONS port. Ext 100. For no reason it would start ringing a room instead of the RAD. My cure was to change programming to wakeup with a tone and then change it back to the RAD. I think Mitel admitted to having a glitch in the software but this all happened around the time the SX50 was being discontinued and they were not interested in trying to fix it.
This system is still in service and about every 6 months I get a call that it is happening again.