i know exactly what you speak of Pheno!!! i have the same exact thing......and i can never get rid of it......it sucks cause the arms just doesn't look as ripped as it can.....but then i'm on my bulking phase..so we'll see in a couple of months after my cutting.
As long as you feel the stretch in your ribcage then you are fine.
GreekGodGen,
You are a big follower of ARnold aren't you? you recommend 50 pullups and seem to do dumbbell pullovers....these are taken from his encyclopedia..just curious that's all.