Steve,
On your server I can see exactly what I could see remotely. Any domain name can be resolved to an IP address without any problem, so it's not a DNS issue. However, trying to use PHP's ftp_connect() to open a connection to any FTP server (I tried a few of my own which I know they work with other on-line servers) it immediately returns false. The only explanation is that, even though your server resolves the domain name to an IP address, PHP is not allowed to connect to the remote server.
Besides an IPTables firewall I am not sure what else on your server setup could cause this. I have not heard of a per-user firewall which can be deployed on a Linux server. Maybe it's something in your specific PHP build? Can you try rebuilding your PHP?
Nicholas K. Dionysopoulos
Lead Developer and Director
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