this has happened to me also i am not sure why becuase i have tested it by thinking maybe some one sat on the keys you know, so i tried to get to work but it would even unlock the doors from inside my house and it did unlock only when i was standing my the window pointing at the car it self so i am at a loss as to why it happening, so far its done it to me about 3 times and one time it started to sprinkle outside and fortunatly i went out at the right time and saw it so it got a little wet but nothing to damage anything inside.