Window Vibrates Open

2008 2551S ..... The window in the slide out behind the couch seems to have a mind of it's own.  At first I thought I was not latching the window shut but found out after checking several times, that as I am driving down the road, the window slowly vibrates open by itself.  Has anyone else had this problem and found a solution? 

I have a 2006 PC2551S and while I do not have a problem I have noticed of the window sliding open (it's pretty stiff in the groove), I have noticed that I have to be VERY careful latching it.  If I don't really push it all the way shut before flipping the lock, it will seem to be okay but not really locked.  You might want to try fooling with the latch a while and see if you have the same problem.