In reply to jezb1:
Mine is my windproof: the makers clearly have far larger ribs than me, so even in size small it's rather loose; and, the fact that it's a smock design, meaning the sleeves have to be quite wide to get one's arms into, combined with the loose fit gives me bingo-wings of fabric to blow and snap in the wind. Of course, it being a wind proof, I tend only to wear it when it's windy, so this is a common scenario. Despite that, I keep taking it with me, as it does the job and is so tough that I can't seem to wear it out.
I am, though, proud to say that I've never yet set fire to the neoprene on my Jetboil!