WordPress MU

In the control panel(Manage-Pages), I want to change the About page direccion,with this link:
wp-signup.php, and when I click save, the link appears:

wp-signupphp, like this, without the point.

How can I resolve this?

You can probably create a page template that does the signup functions. And then you can have your perms looking like anything you want without the need for php.

I havent done it, so just an idea.

Edit your template to include a link to the signup page instead of to the about page.