dolphin dx3 climbs the walls and steps but isn't sometimes flips to side instead of staying upright

by Daphne
(Slidell)

Dolphin DX3 was working intermittently. We replaced the cord and it runs well now however it doesn't seem to right itself after climbing a wall. It rolls slowly down and flips on it's side. It does fine as long a s the surface is flat. The new cord has only one small float, the old one had two. I wasn't sure if that made a difference.