Mine's been sort of doing it for two years. It does stop on the button on the way down, but when you pull up on the button, it continues it's journey down. then only comes up in 3 or 4 inch bursts. Tried new motor, new mech., sprayed lithium everywhere, nada. Suspect door sill rubber now, because when I bent it back this weekend 'just to see if it was that', I got 3 or so clean operations....