Can Edit Posts but Not Pages After Upgrade to 2.7

I recently upgraded to 2.7, and pretty much everything seems to be working alright on the site itself. However, in the admin area I can do everything except edit or add new pages. I can edit posts, but not pages. Here is a screenshot of what I see when I try:

Screenshot

As you can see, there isn’t an error, but the box to edit just isn’t there. I’ve tried everything I can think of, I’ve searched for answers, I deactivated all plugins, I reuploaded the wp-admin folder. I get the same thing with IE or Firefox.

I can’t find an example of anyone else getting any kind of error like this, so any help would be greatly appreciated.