Not sure my Bob doesn't have technical difficulties.  I am receiving a replacement.  He is supposed to program himself and it gets stuck under my sofa constantly.  Now it just goes in circles.  When it works though, it is amazing.  I have a long hair cat and short haired dog.  When I empty the basket with each use, it is amazing what all he picked up.  I hope the new one will program better and I will be in love.