I've got a very strange and scary issue on one of my WordPress 3.4.1 sites. In admin, when I click into Pages, it shows both my Pages and my Posts. It does not do the reverse -- in my Posts I only see posts.
In my Pages display, when I click to edit on one of the Posts that I see listed in there, it takes me to Edit Post (not Edit Page), so it knows it's a post at that point.
So the whole problem can be boiled down to the Pages display in admin it's grabbing both "page" and "post" post types. What gives!!
I don't know if it's related, but in my Media library search no longer works. I'd discovered this a couple weeks ago and had already deactivated all plugins.
I've got a few custom post type plugins running: Types & Views, Formidable Pro and Custom Post Types UI (currently deactivated), if these matter.