The pin does have a bit of adjustment, sliding it back, to make it clip in a little harder. There is no grommet for the closed position hole, only for the vented position. Even after tightening the latch mine still comes unlocked in bumpy terrain but I've never had the window open up. The struts keep it closed pretty good. Don't know if shimming it UP would reduce the tendancy to pop off or not. It might.
I still prefer the open front window to the fixed window on the new models. Side vent windows wouldn't work in my trails. I'd forget to close them and smash them on a tree for sure!