I have a Hincapie jersey that does what I think you are talking about. I think it's because (1) the material is SPF rated and a bit thicker than some other jerseys I own and (2) the zipper is a thicker heavier type. If I am standing up straight it lies flat. When I lean over it bumps out along the lower half. But once I am riding it's a comfortable jersey. Breaths well in hot weather. Nobody is taking pictures of me to sell their product so I just use the jersey and don't worry about it.