I am using WordPress 3.5 MU install

I use a MU install for test sites I am working on before I push them live, Attachments was not showing up on the portfolio custom post type. So I follow the following steps.

I disable the default instance by adding the recommended line to my wp-config.php.

Then I added the listed function to my functions.php

It now shows up fine in my custom post type, but when I click on Attach Files and then select an item and click Attach. it will close the window but not show up in the Attachments meta. Tried to update the post and refresh still doesn't show up. I would be more then happy to offer any of my resources to try and figure out the issue.