I'm using an old "big red ball" Logitech Marble Mouse USB with a Dell Latitude laptop. Lately the cursor consistently drifts diagonally to the lower left. If I hold the ball still, it keeps drifting!! This is a true pain!! If Anyone knows how to fix this, please shared your wisdom! thanks.
This is normally caused by a dirty optical sensor under the ball, you need to remove the ball and clear out any dust or hair particles that might be interfering with its operation, I had the same situation on a laser mouse where i had drifting, and even with blowing onto the lens it didn't help until i noticed that there was a stubborn hair in front of it, got that out of the way and everything worked great