Hi Lee, what platform are you using? Worpress? Joomla? PHP custom script?
Usually a blank page like that indicates a fatal error for php. Check your error reporting level to see if it is off.
am using wordpress and my server emailed me this morning saying
We can confirm that PHP works fine and the wp-admin and other php scripts are working fine.
Unfortunately we do not provide scripting help, as this is beyond the realm of service that we provide. We suggest searching on wordpress forums for scripting help.