It seems as though I've read something on here about one or more models of Glocks that have trouble operating smoothly with a light on the rails. Can't find it and I certainly can't remember which gun it was. Something about the frame not being able to flex properly under recoil? I'm shooting a local "low-light" match tomorrow night (Thursday) and I don't want to take the wrong Glock with my cheap little light. Anyone have any ideas?