Hi thesanerone,
Check these lines 45-47:
    wp_register_script( '
wp-ajax-post-sort',  plugins_url('
wp-ajax-post-sort/
wp-ajax-post-sort.
js'));
	//wp_enqueue_script( 'jquery-ui-sortable' );
	wp_enqueue_script('
wp-ajax-post-sort', plugins_url('
wp-ajax-post-sort/
wp-ajax-post-sort.
js'), array('jquery'), '2.50', true);
... it must looks like this:
    wp_register_script( '
wp-ajax-post-sort',  plugins_url('classipress-ajax-post-sort/
wp-ajax-post-sort.
js'));
	//wp_enqueue_script( 'jquery-ui-sortable' );
	wp_enqueue_script('
wp-ajax-post-sort', plugins_url('classipress-ajax-post-sort/
wp-ajax-post-sort.
js'), array('jquery'), '2.50', true);
In your updated version you are calling the .
js at your old plugin folder so in case the user deletes it the filtering will simply not work for sure... Now you own me some money 
Best regards,