Thanks for your further thoughts.
I thought the most "polite" thing to do, in fact, was to try installing the FileZilla client, rather than continue to fiddle with SmartFTP.
I evidently have some sort of conflict between my XP Home desktop, from which I tried running FileZilla client, and the networked XP Pro tower which is running the FileZilla server.
Here is the text of what I run into:
Status: Connection established, waiting for welcome message...
Response: 220-FileZilla Server version 0.9.24 beta
Response: 220-written by Tim Kosse (Tim.Kosse@gmx.de
Response: 220 Please visit http://sourceforge.net/projects/filezilla/
Command: USER hans
Response: 331 Password required for hans
Command: PASS *********
Response: 230 Logged on
Response: 215 UNIX emulated by FileZilla
Response: REST STREAM
Response: MLST type*;size*;modify*;
Response: 211 End
Status: Retrieving directory listing...
Response: 257 "/" is current directory.
Command: TYPE I
Response: 200 Type set to I
Response: 227 Entering Passive Mode (192,168,1,102,10,45)
Status: Server sent passive reply with unroutable address. Using server address instead.
Response: 425 Can't open data connection.
Error: Failed to retrieve directory listing
Response: 421 No-transfer-time exceeded. Closing control connection.
Error: Disconnected from server
Please note, this username and password had been successfully used by a friend from a remote PC, with success. And, FileZilla client on the XP Home desktop works successfully with outside ftp server sites.
Once again, if there is a tweak I am missing to make this work, I will be most appreciative of a suggestion.