I thought there was an issue with my 9650 as it would not climb the walls. So I set it to "lift" so I could check it out and it wouldn't do that either. I "helped" it up by slightly lifting on the cord and got it to the surface. When I opened it up the filter was FULL of basically sand/dirt! Wow never saw so much but this is the first cleaning of the year so I expected a little more. It's back in doing its thing for a 3rd run now. This thing cleans SO well. I really love it!