i've got this black rubber molding for my window, and it's being a major pain. it's got the two notches for the case and window, and a third in the middle for a rubber locking strip. the problem is, no matter what we try to put it on first, the case or the window, it won't stay flat and attatched to it, and therefore we can't get the window all the way in without part of it falling off and the window eventually shifting. is there some secret to this, or has anybody figured out any helpful tricks?