I called Garrett and found out what I was doing wrong. Possibly. Seems I might have been pushing the pinpoint button while the coil was over the target. I need to push the pinpoint button when the coil is beside the target, then slide the coil over the target once the button is already pressed. I can't say for sure if this is what I was doing, but I'll make sure I do it the right way and see if that rectifies the problem.