Proxmox 3.0 web ui on port 443 instead of 8006

I would like to change the webui port on my Proxmox 3.0 installation to port 443, not 8006.

I notice it is hardcoded in pveproxy, and changing the port to 443 gives the following error:

pveproxyunable to create socket - IO::Socket::INET: Permission denied

This appears to be running as www-data, and I CAN change the port to some of the higher ports like 8007 or 9000, but not any of the lower ports.... do you know what might be causing this, and is it possible to change the port to 443?

Thanks!