Hi
Not really sure why you are getting this error, but I can tell you how I've set Dreamweaver up to ftp upload to my webspace.
In the "Site Definitions",
under "Local Info",
"Site name" can be anything you want.
"Root folder" is the folder on your local hard drive where your web site pages are stored, e.g. "D:\Web\"
I've got the "Refresh local file list automatically" option ticked.
For the "Default images folder", I've got a folder called "images" inside my local root folder, and the path here points to that location, e.g. "D:\Web\images\".
The "HTTP Address" is the URL to access your webspace with a browser, e.g.
http://homepage.ntlworld.com/<NTLUSERNAME>/"
I've also got the cache enabled.
Under "Remote Info",
Access is "FTP"
"FTP host" is upload.ntlworld.com
Login is your NTL USERNAME
Password is your NTL PASSWORD
You may have "Passive FTP" ticked, but I haven't. If you haven't, then your firewall has to accept connections from the FTP host. Passive mode does not require any further setting up of any firewall, but I've found the connection sometimes drops on very large files. I would recommend you start with "Passive FTP" ticked.
Under "Site map layout",
"Home page" is set to the "index.htm" file stored locally, e.g. ""D:\Web\index.htm".
That's about it. Don't forget, for your web space to work on NTL, you need an "index.htm" file stored in the root folder (i.e. not in a sub-folder)
Hope this helps.