He called Adelphia and they insisted the cable connection is fine.
He called Dell and they insisted the computer is fine, and that Opera was likely the problem. IE, however, acts the same way.
He called me. A while back I installed RealVNC on his machine so he could start it up and let me look at his machine from mine. We established a RealVNC connection very easily and I had complete and very fast control of his PC. I proceeded to check out all that I knew to check (not a lot, really), and pinged a couple of web sites by their URL. I can find nothing wrong and, with both the VNC and the pings working very well, I think its safe to say that the cable connection is good.
I uninstalled Opera, rebooted, and tried again with IE - no change.
I did a little research and found that a corrupt IP stack might cause the problem. From microsoft.com, I got the info on netshell and tried resetting the IP stack. I rebooted and tried IE again - no change.
I'm out of ideas. Any help anyone can give would be really, really appreciated.