[Plugin: Advanced Most Recent Posts Mod] Remove Widget Title

To completely remove the widget’s main title, make this adjustment in adv-most-recent.php (v 1.6.5.1)

Find line 25, it looks like this:
$title = empty( $instance[ 'title' ] ) ? __( 'Recent Posts', 'adv-recent-posts' ) : apply_filters( 'widget_title', $instance[ 'title' ] );

Replace that line with this:
$title = empty( $instance[ 'title' ] ) ? '' : apply_filters( 'widget_title', $instance[ 'title' ] );

http://wordpress.org/extend/plugins/advanced-most-recent-posts-mod/