First attempt at installing an AP(R) -R adapter on NEC 2000 IPS telephone. Telephone is a DTR-16-1, and the adapter works fine on a key system but, once connected to the PBX the analog port has side tone just no dial tone. If I lift the handset or press the speaker key the analog port gets dial tone but, just lifting the handset on the 2500 desk set all you get is side tone. I am unable to find any help in searching the 2000 IPS manuals and very little in the IPK key system manual. Does anyone have any ideas?