Passenger Side Mirror Keeps Moving

I have a 1999 Montana that is moving the passenger side mirror every time the key is cycled.

Any ideas what I can do to fix it?
Thanks!

Mine vibrates out of place and have to adjust it nearly every time I drive it...
Anyone else have any ideas?

Thanks for the response! Maybe it is just vibration doing it. Any thoughts out there on how to fix it? It's VERY annoying!

I have a '02 Montana with the same problem. I think it is when ever someone shuts the door, the passenger side mirror will moved out of place. Anyone out there know how to tighten up any settings on the mirror or what is causing the problem.

Thanks,
DB

Bump. Same problem here