Solution for WP 2.7
Replace $suffix = 2
With return 0;
You will find $suffix = 2 twice in wp-includes/post.php
or another solution
Got a problem with WP-O-Matic creating duplicate posts? Or just WordPress in general. Me too.
I wrote a script to run on a regular basis so sort this problem out.Create wp-posts-cleanup.php in your wordpress/wp-config/plugins/ directory,