Hmmm...hard to say without seeing it in person, but it looks like the vest itself might be causing the problem. There's a wierd wrinkle that's letting that plate jut out. There's not any stretch in the vest material is there? If there is, that'll give you fits (I know from experiance). The other thing is to make sure you give a good Picarding (sharp downward tug) when you put your vest on to make sure it lays flat and tight against your body.