Every several months somebody runs into a problem with FTP. Unfortunately they are not always the same problem. But the basic troubleshooting steps are mostly the same.
To begin, look at the topic in this form title "ZTERM FTP problem" dated 14 January 2002 (change the view option at the top of the screen to show all items, or search for "FTP"). That describes one possibility.
It assumes that you are able to FTP using the Microsoft command line FTP (i.e. from the console window). If that doesn't work either, then it suggests something more fundamentally wrong at the network level since ZTERM and the Microsoft FTP command use different FTP libraries.
I don't know whether this is applicable, but many times in the past, ZTERM FTP and other network-related problems have been resolved by updating the Windows software on the PC in question. In particular, updating to the current version of Internet Explorer will refresh virtually all of the network-related modules. Since ZTERM just uses the standard WININET library, most FTP problems are less related to ZTERM than to some aspect of Windows itself.
If none of those ideas help, perhaps more details about the specifics of the site - network configuration, Windows OS versions, whether/which PC's work and which don't, which other FTP utilities work or don't work, etc.
