Re: wp-signup.php is a blank page
@Xevo, I am having the same problem. I inserted your redirect function and now get the following error message on my site homepage:
“Fatal error: Call to undefined function add_action() in …../public_html/wp-includes/functions.php on line 3427.
I inserted an exact copy of the code you pasted above (except that I changed domain.ext to my own domain name.
I’m not sure why I get this error message. 
