When the receptionist forwards her phone to someone else and they get a phone call, they can answer it, but when someone calls while their on the phone it automatically dumps them into voicemail. It doesn't do it for the receptionist. Just when the phone is forwarded to someone else. The rec. phone is a model M7324 the others are a M7310. The M7310's does not have access to pick up on the last 4 lines out of 9. Is that why? Or is there some programming I can change?