My Buddy has a garage door opener. It's a Legacy from Overhead Door Company. The "opener" i.e transmitter on the wall is a Code Dodger. The receiver is a Multi Code.
Here's the problem. The original receiver went bad and Overhead came out and replaced it. It now works fine with the exception that any minor power blip (outage) causes the door to open on it's own. Once open, the receiver has to be unplugged to re-set before it will work again. Overhead has been back but they have not been able to diagnose the problem. They say everything is fine. From my perspective I would say the receiver either has an issue or it's the wrong receiver. With the exception of this one problem it works fine.