loop-master.php

<?php

    // Show Master-Class post type if it is Master-Class
        //query_posts($query_string  . '&post_type=master_class&posts_per_page=3&paged=$paged');
        $type = 'master_class';
        $paged = (get_query_var('paged')) ? get_query_var('paged') : 1;
        $args=array(
            'post_type' => $type,
            'post_status' => 'publish',
            'paged' => $paged,
            'posts_per_page' => 3,
            'caller_get_posts'=> 1
          );
        $temp = $wp_query;  // assign original query to temp variable for later use
        $wp_query = null;
        $wp_query = new WP_Query();
        $wp_query->query($args);


 ?>
<?php if($wp_query->have_posts()) : while($wp_query->have_posts()) : $wp_query->the_post(); ?>

        <div id="post-<?php the_ID(); ?>" class="master_item">
            <div class="post_main_img">
                <?php
                    if ( has_post_thumbnail() ) {
                        the_post_thumbnail('single-post-thumbnail');
                    }
                ?>
            </div>
            <div class="master_item_content">

                <h2><a href="<?php the_permalink(); ?>"><?php the_title(); ?></a></h2>
                <?php
                    $master_info = get_post_meta($post->ID, 'master_info', true);
                    if ($master_info !== '') {
                        echo $master_info;
                    }
                ?>
            </div>
            <div class="clear">&nbsp;</div>


        </div>

<?php endwhile; else :// End the loop. Whew. ?>

    <div id="post-0" class="post error404 not-found">
        <h1 class="entry-title"><?php _e( 'Not Found', 'twentyten' ); ?></h1>
        <div class="entry-content">
            <p><?php _e( 'Apologies, but no results were found for the requested archive. Perhaps searching will help find a related post.', 'twentyten' ); ?></p>
            <?php get_search_form(); ?>
        </div><!-- .entry-content -->
    </div><!-- #post-0 -->

<?php endif; ?>

<?php /* Display navigation to next/previous pages when applicable */ ?>
<?php if ( $wp_query->max_num_pages > 1 ) : ?>
    <div id="nav-above" class="navigation">
        <div class="nav-previous"><?php next_posts_link( __( '<span class="meta-nav">&larr;</span> Older posts', 'twentyten' ) ); ?></div>
        <div class="nav-next"><?php previous_posts_link( __( 'Newer posts <span class="meta-nav">&rarr;</span>', 'twentyten' ) ); ?></div>
    </div><!-- #nav-above -->
<?php endif; $wp_query = null; $wp_query = $temp;?>