I leave mine on the wall, without a problem.
Last weekend camping, I left my new MacBook out, and when my son and his fiancee brought thier two Labs into the TT, DW was worried that the laptop might get chewed or stepped-on (they are still pups), so she stuck it on top of a wall-mounted shelf for the DVD player that I installed in the TT bedroom. She told me it was there, but I soon forgot completely about it, and it rode there all the way home, without vibrating off of the shelf.
2014 RAM 2500 Laramie 4x4 Quad Cab w/Cummins Turbo Diesel, 2009 Rockwood 2607, and 3 'yaks!
300W of Suntech Solar, a Rogue MPT-3024 Controller, and a Xantrex PW2000 Inverter