This is quite possibly what happens with mine, due to the weak actuator usually pushing the button up far enough to open the door, but not enough to put the latch lock rod in it's full up/open position. I will say that I've tried closing the door very gently and only to it's partially latched position, but that's really the only explanation that makes any sense. I don't think it's electrical. I've noticed that if I remove the black plastic lock button the actuator works much better. I've even mounted the button in my drill and sanded it down a bit to reduce the friction on it in the door's eyelet and put a few drops of oil on it. This helps, but not enough. I should probably remove the interior door panel and see if any adjustment/alignment of the lock rod and/or lubrication will help. I should just install a new actuator, but I just don't have the time or ambition right now. Too many other more pressing projects with my ST.