FTP connection through Proxy: protocol violation but with FTP program it works

Thank you for your help.

I've tried what you suggested... It seems to be the right direction, but it still doesn't work. I still get the same answer (protocol violation).

I traced with wireshark again:

ToDestination:

GET ftp://ftpUser%40ftpHost:ftpPassword@ proxyHostroxyPort/ HTTP/1.1
Host: proxyHost: proxyPort
Proxy-Connection: Keep-Alive

ToSource:
220 Ready

That's it.

Then I tried with IE7, I just put ftp://ftpUser%40ftpHost:ftpPassword@proxyHost: proxyPort/ on the command line. It works!

When I traced this command, I've got the same result as I got when I tried with my FTP-program...

Could HTTP/1.1 be the problem?