puzzling Rewrite rule

gistfile1.aw

<?php

function add_mypage_var($public_query_vars) {
	$public_query_vars[] = 'blub_key';
	return $public_query_vars;
}

function createRewriteRules() {
	global $wp_rewrite;

	$new_rules = array( '%category%/(.*?)/blub_key/([a-zA-Z0-9_]{5,5})-([0-9]{3,3})$' => 'index.php?p=' . 
					$wp_rewrite->preg_index(1) . '&blub_key=' . 
					$wp_rewrite->preg_index(2) . '-' . $wp_rewrite->preg_index(3) 
					);

	$wp_rewrite->rules =  $wp_rewrite->rules + $new_rules;
	return $wp_rewrite->rules;
}

function get_rewrite_urls(){
	global $wp_rewrite;
	return $wp_rewrite->wp_rewrite_rules();
}

function do_flush_gear(){
	global $wp_rewrite;
	$wp_rewrite->flush_rules();
}

add_filter('query_vars', 'add_mypage_var');
add_action('generate_rewrite_rules', 'createRewriteRules');

print_r(get_rewrite_urls());
var_dump( get_query_var('blub_key') ); 

#do_flush_gear();