[Kieran]

If you wish to move to CPanel you need to raise a support ticket. A new account will then be setup for you on a CPanel server and you can move your content accross in your own time. When you are ready, flip the DNS settings on your domain(s) and request your old HSphere account be deleted.

As for your problems, I'm not entirely sure why this is happening. If you try to modify php settings in .htaccess (such as register globals) do you end up with a 500 Internal Server Error?