Sorry for posting in the old thread. Yeah, you are right that other themes change the background after activation but I thought with your nice settings menu there could be an option to not change it (optional).

And because you asked a few pages earlier: The IM conversation icon is still the black envelope (same icon as the SMS icon) with a red "IM" in the bottom left corner. It would be nice if it would be a completely different icon like a speech bubble or something like that.
I think you have used it some time ago already and then switched to this icon (for whatever reason).