Apache 400 Absolute Path for Blogs

Question

Here is an example of a blog with this issue.

It uses Apache to send a 400 error, but keep the url as is.

Is there a way in Apache using a .htaccess file to keep the url as is so the PHP script can do as needed with it, but not send a 400 error?

The site works fine in some browsers, but those like IE and mobile browsers have there own error pages so they get nothing.