wondering pointer

[fastwheels]

Hello my friends, it's me the rookie with a question for the great minds on this site. I am using a logitech roller ball mouse sue to a bum right hand . The mouse works well most of the time but I getting a problem that my pointer will start drifting across or up the page by itself. I can move the pointer to a place on the page and while still holding down the left button the pointer will start drifting . any ideas? once more thanks for your time and help . fastwheels