"Failed to copy file" Error when publishing VS2008 application via FTP

I need to share a little .NET console application with a couple random people, and instead of emailing it I thought I would publish it to my web server as a "Click Once" application.

Simple right? Wrong! I'm trying to publish via FTP and getting the following error:

Failed to copy file 'C:\Projects\scrappydog_projects\Google\libgoogle-data-mono-1.3.1.0\src\GoogleGroupCleanup\bin\Debug\app.publish\Application Files\GoogleGroupCleanup_1_0_0_0\Google.GData.Client.dll.deploy' to 'ftp://scrappydog.com/GoogleGroupCleanup/Application Files/GoogleGroupCleanup_1_0_0_0/Google.GData.Client.dll.deploy'. Unable to add 'Application Files/GoogleGroupCleanup_1_0_0_0/Google.GData.Client.dll.deploy' to the Web site. Could not find a Web server at 'scrappydog.com' on port 21. Please check to make sure that the Web server name is valid and your proxy settings are set correctly. If you are sure that everything is correct, the Web server may be temporarily out of service.

I can watch the files being created on the server with a ftp client, and so I know it's connecting, but somewhere at the end of the process something else fails, and rolls back the whole process and deletes the files... aargh...

I've found lots of references to the same problem, but no solutions... anyone? anyone?

UPDATE: This issue seems like it may be firewall related. Publishing the same project from a different computer on a different network works fine...