We are trying to add 2 lines to this system. Lines 1-3 are dial tone, and line 6 is connected to a paging system. We connected COs to lines 4 and 5, programmed them as connect in 03, changed the ringing assignment in 09,10 and checked that the buttons are programmed on the extensions by going into the program mode on the phones but we still can not pickup lines 4 or 5 on the system or get ringing in on them. When pressed the buttons give a reorder tone.