When I hold the base perpendicular to the ground, the lid will fall closing it or cracking it open. Is that supposed to happen at all? I got the whole display assembly replaced and I can't remember how it was before. I found out the behavior when testing it. I know MBAs don't have a tight hinge, but what about cMBP, 15"? I've already done some research and it seems there are mixed opinions. Some say it's by design, other say it's a flaw. Also, let me stress 15", as the lid is obviously heavier than the 13" one, so maybe 13" stays in position but 15" not due to weight. What do you guys think?