I have just jailbroken my iPhone 4 4.2.1 using greenpois0n and all is fine except one thing...

Some stock apps (namely photos, camera, maps, gamecenter, etc...) are not theming! I have downloaded about 5 or 6 themes and I've tried them all and its always the same icons that aren't theming. They are just left as the default icon. What is happening?