If you experience white pages during the registration process, your server does not allow to use the function fopen() with external URL's. This is true for server with PHP Safe Mode enabled, or explicit permissions. White pages after some time mean that your server shuts down the page process too quickly. In order to handle also the most exotic IP and email, you should allow 60 seconds of script execution.

To solve these problems you must have server access or tell your hosting provider. If the Safe Mode is not enabled, you may try to add to your configuration the following line and adjust the script timeout value to your needs:

@set_time_limit(60);