Thematic remove Header bits.

gistfile1.php

// remove header bits, previously this was done to Thematic itself, but you aren't suppose to do that, it is as simple as.
function childtheme_remove_headerbits() {
    remove_action('thematic_header', 'thematic_blogtitle', 3);
    remove_action('thematic_header', 'thematic_blogdescription', 5);
}
add_action('init', 'childtheme_remove_headerbits');