For those of you running Postmash, this appears to be a fairly simple fix. Change the following line(s) of code in postMash.php:
//get pages from database
$pageposts = $wpdb->get_results("SELECT * FROM $wpdb->posts WHERE post_type = 'post' ORDER BY menu_order");
to this:
//get pages from database
$pageposts = $wpdb->get_results("SELECT * FROM $wpdb->posts WHERE post_type = 'post' and post_status NOT LIKE 'auto-draft' AND post_title NOT LIKE 'Auto Draft' ORDER BY menu_order");
This will prevent postMash from finding any auto-draft entries in the wp_posts table (including those already eroneously published). If you already have published “Auto Draft” posts, either return them to draft status or delete them.
Oh, and if you actually want to use postMash with a post titled ‘Auto Draft’ you can ommit “AND post_title NOT LIKE ‘Auto Draft'”
–Chillin’ in Portland