A:
You have to deregister the phone and it will work. Press Menu / Select, then press * 7 8 9 0 #. The window will say TEST BASE, scroll up with arrow (Vol) buttons until it says TEST HANDSET and hit Menu / Select again. Window says SW VERSION, scroll to NEXT PAGE. . . Hit Menu / Select again. It'll say REGSTR CLEAR. Hit Menu again. It'll make the little three-note "success" beeps. Then you can pair it with the base you want to pair it with, using the Find Handset button and the base and the Pound button on the handset. The same exact handset is used for both the 6114 and the 6124.