Footloose

My 2004 RX 330 has a recurring problem with the power rear hatch. When using the dash button or remote, the door opens about an inch or two, then changes directions and closes. The dealer already replaced the ECU under a bulletin. Problem seems to be temperature related and occurs all the time during very hot or very cold days. At other times it will work intermittently. Of course it always works when its in the dealer's service bay!! Has anyone had this problem --- and found a solution??? Thanks!