The reason you get the false notification is because there is not enough reflection coming back to the photosensor. When reflection rate falls below the threshold setting, Garadget reports the door as open. The possible reasons are:
- laser not pointed at the reflective tag
- obstruction from release rope, webs, insect nests etc
- ambient light washing out the reflection
Although cases are rare, It is also possible that the laser is not doing too well - you’ll notice that it got dimmer. In this case you can send your unit (just the main body; leave wiring and mount in place) for warranty repair to the address in this post. Typically you get the repaired or replaced unit in around 10 days or less.