Setting up a secondary Call Pilot for Enhanced Call Center on a Norstar MICS 7.1 EX. I'm trying to simply assign a CDN to skillset 1 to enable it. No matter what DN I use (unused B1 DN, unequipped B2 DN), I get the message "The Control DN is in use by another device or service." Tried to set it up through the telephone interface, get the message "CANNOT CONTINUE" then "Exit" when I input the DN. Is there a trick to this? I've tried about 20 different DN's that aren't currently in use. Thanks!