Once every 2 days, whilst I am on my computer my trackpad glitches and the drag is constantly on. It is hard to explain. Basically, when you move the mouse (not holding down) your text gets highlighted or you select whatever you have dragged across (just like if you were holding the trackpad down). If you click, then that selection stops, but when you move it again it selects. Restarting the computer solves the problem, but only for a limited time. I have tried going to the System Preferences and turning off drag lock/dragging. This did not help. No I am not holding down the button or something stupid like that, it happens spontaneously. It may be when I am on Facebook, TouchArcade or neither. There seems to be no connection.
Something similar just happened to my fiancé. He had a defective battery that bulged so much it was pressing the circuit panel into the trackpad from below. You might want to check that.
