Hi Acrylian,
Thanks for your help. I agree the PHPinfo looks a bit short, but I'm unfortunately not too familiar with PHP so I know neither how to fix that now whether it needs fixing. I did install GDlib (at least, I downloaded the RPM and ran rpm -i; I don't really know whether it worked). Originally the trouble was that PHP 4.4.7 was on the server. I attempted to upgrade this to 5.0.4; I'm not sure whether that was successful, either, as I did so through cPanel and the messages were cryptic at best, especially for a relative linux novice.
I am loathe to install PHP from source -- I would probably mess up more than I would achieve. However, I am not completely opposed to the idea.
My server was setup using a template provided by my employer for virtual private servers, so while it's possible the setup was incorrect, I believe it unlikely. This might also answer your last question, but I'm not quite sure what you meant. This is a virtual server running Red Hat Enterprise Linux 4 and had cPanel pre-installed. It's running on a hardware node running Virtuozzo in a datacenter. It's not running on a server in my living room (that server had better success at installing zenphoto

).
I hope that perhaps clarifies a bit. Thank you.