[NSFW] Login launches a php file request

Make sure your host hasn’t changed anything.

Make sure you host has httpd.conf correct

May need to add:
AddType application/x-httpd-php .php

to your httpd.conf file.

Also make sure you have enough memory allocated to PHP:
Methods for increasing the amount of memory a PHP script may consume.

1. Use the memory bump plugin from http://wordpress.org/extend/plugins/memory-bump/

2. If you have access to your PHP.ini file, change the line in PHP.ini
If your line shows 32M try 64M:
memory_limit = 64M ; Maximum amount of memory a script may consume (64MB)

3. If you don’t have access to PHP.ini try adding this to an .htaccess file:
php_value memory_limit 64M

4. Try adding this line to your wp-config.php file:
define('WP_MEMORY_LIMIT', '64M');

5. Talk to your host.