Last week, after returning from an uneventful commute from work, as I set down my helmet I noticed that the left front top vent on my helmet (Arai Signet GTR) was gone. All that's left is some sticky V shaped gluey gunk. It was there when I left, because I checked to make sure it was open. To my knowledge (I think I'd know), nothing whacked me in the head hard enough to take it off, so I have to assume it just blew off. I've never dropped the helmet, keep it in the bag when I'm not wearing it, and it's less than 2 months old. Has this ever happened to anyone? I'm sure I can get the piece replaced, but it makes me worry how well the rest of it's constructed if the plastic parts can't stay on....