I found that the title of the meta box cannot change via the cctm plugin. It shows "Custom Fields" as default, which is pretty annoying to see.
So I decided to change it in function.php, here is my code :
add_filter('add_meta_boxes', 'change_meta_box_titles');
function change_meta_box_titles() {
$wp_meta_boxes['my_post_type']['normal']['core']['cctm_default']['title']= 'Details';}
But it failed to work, any idea?