I just upgraded to 2.7, and my blog works fine as far as I can see. I can write and edit posts. The problem is that I can't update my profile page, or enter my WordPress.com API key to activate a plugin, for example. I get the following error message when I try:
The requested URL /stuff/wp-admin/(EmptyReference!) was not found on this server.
Additionally, a 404 Not Found error was encountered while trying to use an ErrorDocument to handle the request.
The EmptyRefence! part leads me to believe that the problem is not in the wp-admin folder (which I have removed and replaced since discovering this problem) but rather in the instructions being generated by the Update buttons.
Any ideas? (I'm not much of a code-head, so please be gentle!)