In the episode where Helga's dad hurts his back so his mom goes to work for Big Bob's Beepers. In one scene, when Helga's mom is on the bed she is talking to the black phone, then the white phone rings so she picks it up. She starts talking to the white phone. When her conversation with the white phone is over, she puts down the black phone and says to the white phone, "So where were we?" I guess the phone signals got crossed.