Same title/url posts don't update they make duplicates

When i have an RSS feed or a pipe create posts, WordPress makes duplicate posts instead of updating the existing post under the new name. The duplicate just gets a number at the end of the url. For example, http://www.example.com/new-post would be http://www.example.com/new-post-1 then http://www.example.com/new-post-2

I am using a program called WP Pipes; however, all of the settings are the same as another site I am using it on, which leads me to believe this is a wordpress issue.

Keep in mind I am using a WordPress Multisite and the other is a stand alone site.