2001 power door

On occasion the side power door will close than open by itself. It will happen a number of times than it will close. Any clues on what it may be. Also is there a way not to use the power door opener. And to use it manually if we want to?

Try cleaning the pad and plunger with a clean cloth, works everytime on my 2000.

Thanks I will try that , it sounds like this is wat it could be.