posted on Jan, 3 2006 @ 08:23 AM
Well, some of the possibilities which come to my mind are somewhat unlikely, but I'm not an electrician.
The best possibility is that a neighbor has a remote on the same frequency. The varied position of the garage door (1/4 open) could be explained in
this way- if they saw it moving and clicked again to stop it. You can check by taking your remote and walking around a short distance outside,
pointing it in various directions and clicking it. If a neighbor's door opens, look into the possibility of adjusting the frequency. If that's not
possible perhaps some kind weak insulation of the sensor could be used to reduce its reception range, but I'm completely guessing.
It's remotely possible that the door is loose, and is therefore shaking slightly, causing the sensors to lose contact with one another and open again
just as you are leaving the garage after closing it- you wouldn't necessarily hear anything because it would sound like the door is still closing.
I suppose an electrical short could be triggering the door, but it seems to me that it would trigger constantly, going up and down until it burned
itself up. It's possible that some kind of physical movement or other condition is causing the short only at certain times though I suppose.
Least of the possibilities in my mind- pests, cats, aliens, chupacabras, or some other entity may be in your garage triggering the safety
If all else fails, write to Tim Allen.