Thumbnail's Not Cropping

Hello,

I had created a theme and added thumbnail support on it, i had added following code in functions.php :-

if ( function_exists( 'add_theme_support' ) ) {
	add_theme_support( 'post-thumbnails' );
        set_post_thumbnail_size( 64, 64, true );
}

and following in index page :-

<?php set_post_thumbnail_size(); ?>

But images are not cropping as you can see here TechnoArea
plz help i want to use hard crop so that every thumbnail will appear with 64*64 on index page