George, is there a setting in iWeb for "passive FTP"? Quite a few hosts require it - and that may be the only problem.
Apparently the setting isn't in iWeb itself, it's in your network settings:
System Preferences -> Network -> (interface) -> Proxies -> Use Passive FTP and I just checked mine and it's checked by default. You could, of course try UNchecking it too - sometimes that works!
All Apple apps use this setting to determine whether or not to use passive FTP for connections. Other (third-party) clients typically have their own setting.
A lot of people complain about iWeb's built in FTP (and Dreamweaver's built in FTP too, for that matter) - you could try Filezilla or Transmit, or FireFTP (extension for Firefox) and publish to a folder and then use the 3rd party FTP. Lots of people find that works very well.
http://iwebfaq.org/site/iWeb_Folder_FTP.html - directions towards the bottom for that option.