I replaced 4 icons in the Orion theme by Jasonevil. The icons have exactly the same name and same dimensions (48x48 / 60x60). The APK won't install. I renamed it to zip and tried to install it in CWM. I the "check for signing" was disabled. This didn't work. I have signed the zipfile with APKSigner from the Google Market but this didn't help either. What do I do wrong?