Not Acceptable (after editing the time of a post)

Constantly getting this error when I try editing the time a post is displayed:

Not Acceptable

An appropriate representation of the requested resource /wordpress/wp-admin/post.php could not be found on this server.

Additionally, a 404 Not Found error was encountered while trying to use an ErrorDocument to handle the request.

I did the automatic update through WordPress to 2.7.1.

Apparently the date of the post is actually changed, its just that error comes up every time i do it.