Wordpress 3.9.1 custom post type problem

I have several custom post types on several web sites. Not long after the update to 3.9.1, my users informed me that one of the post types was no longer visible. I could still access it by going to wp-admin/edit.php?post_type=[custom-post-type-here] however, the link on the admin bar was gone.

The solution that I found was to set the add_action() priority to 2 on a couple of them.

[update]

This "fix" doesn't seem to work consistently in all cases. When trying to duplicate the solution I was unable to achieve the intended result. Alternatively, I have noticed that Wordpress doesn't seem to like showing more than 5 custom post types.