My 09 had the basket fall off into the tank as well. Not very uncommon from what I've read over the years. It happens on other Nissan models as far as I'm aware. All the symptoms everyone had sounded like a broken pump housing to me.

you know a lot of the time you can pull out the sending units and on the arm is a little sweeping contact that rubs against a potentiometer strip on the sensor cleaning that with some alcohol can fix it if it is just covered in deposits. if its worn through its bad. also sometimes you can bend the little contact to put more pressure on the strip. saves replacing $x00 sending units

see here