If you're using a settings bundle for your settings, you need to exclude it from the build process for your app in the release configuration. A #ifdef DEBUG
macro will only help you for code that you want to exclude from compilation - it won't help excluding a settings bundle.
You need to add a build phase to include/exclude your settings bundle based on the build configuration you're using. Check out How can I conditionally include a file based on build configuration in Xcode? for help with doing this.