add_custom_background is deprecated since version 3.4!
Use add_theme_support( 'custom-background', $args ) instead.
add_custom_image_header is deprecated since version 3.4!
Use add_theme_support(' custom-header', $args ) instead.
When a function is deprecated it means it has been replaced with a new one, so it’s no longer supported. You have to use the newest functions as the deprecated ones will be removed in later versions. Theme authors would then have to update their themes. So I am updating mine.