twentyten_setup can't be removed in a clean manner — at Version 2
|Reported by:||jorbin||Owned by:|
Description (last modified by dd32)
Since child theme's functions.php files are loaded first, you can't use remove_action( 'after_setup_theme', 'twentyten_setup' ); to remove twentyten_setup. The attached patch reverts the change from  and raps twentyten_setup in a functions_exists call to make it pluggable.