For WP to work correctly you'll need to upgrade your PHP version to "Intermediate". You can do this at:
http://x10hosting.com/account . After your PHP upgrade request is accepted, it can take up to 6-12hs for it to update on our servers.
You should be able to enable/disable registers in the WordPress AdminCP. You should ask this in the WP forums. We don't support 3rd party scripts, this section is only for hosting account related support.