About two weeks ago I recently put on new springs, balanced the tension, and it ran great for two weeks or so. Now when the garage door opener is activated, it goes up four or five inches and then stops and returns to the ground. When I use the emergency release, the door will open quite easily, too easily at first, and when I close it, it won't stay all the way closed. It remains open by an inch. I "repaired" it the other day by loosening the tension so that it would not open with the push of a finger, activating it while disengaged, and running the opener through a full cycle twice, and then when I reengaged the door it worked well for about four openings before reverting to the old misbehavior. Any clues?