I have a 12" Powerbook about 7 months old. Lately I the cursor has been acting funny. It jumps around all over the screen where I don't want it to go when I drag my finger across the touchpad. Or, it seems to get "stuck" as if a wall is in the way or something when I try to move the cursor to specific areas of the screen - especially the dock. Its movement it all around jerky. Basically it acts the way it does when you try to use the touchpad with another finger resting on it, or the way a mouse does when the ball or surface underneath is dirty. I cleaned the touchpad to no avail and my hands are clean. Anyone experience this before? What can I do?