cursor and input jump around when typing
while typing in any application the cursor and input point jump backwards to a previous point in the text. My teackpad was suspected and replaced but the problem persists. What to do?
Mid 2009 MacBook Pro 15 inch, 2.66 GHz core 2 duo, 8 GB ram, OS X 10.10.4
MacBook Pro (15-inch Mid 2009), OS X Yosemite (10.10.4)