Why does my garage door begin by itself? i have a genie garage door starter. sometimes, right after i close...

i have a genie garage door starter. sometimes, right after i close the garage door, it reopens by itself. this happens right after the door completely shuts.
Clogged problem?
Answers:    first article, check the sensativity of the down force of the operator, if it is too questionable, it can do that,, second, check the bottom limit setting of the worker, if it is trying to close the door too much it will do that also, if it was your sanctuary eyes, the door wouldnt go down at adjectives....
How do I replace a stubborn spout stem?
There is an adjustment on the motor for the down cycle - there is a procedure to adjust the motor contained by the owners Manuel. It usually consist of placing a board (2"x4") and making adjustments by closing the door. Id say aloud the motor is being told that the condition exist that something is beneath the door - Its a built surrounded by safety device to preserve children or animals from being hurt - Hope this make since. There is a couple of other things it could also be - but most likely this.