I guess its a feature not a bug. You receive change to other addresses then the input addresses. This is good. I have not looked fully into this but receiving change onto another address then the input addresses somehow protects your privacy plus you would even be safe if quantum computer would exist as you could easily never use the same address twice. I am not sure if you can configure if armory receives change to the same address or to a new address which will be labeled [[change received]]. What you can do, however, is use coin control in expert mode so you can set everything manually. Please make sure you don't end up being the guy who pays 200 BTC transaction fees because of a number entered in the wrong field.