I don't know if this is a server or client question yet!

I've a server with vsftpd. I use it with leechftp, filezilla, dreamweaver, vith some small problems but more or less it works.
Yesterday I tried to connect with the command line fto on another linux server. The connection was ok but no command (ls,send,put,...) worked!
I tried also to force active mode and to change client to ncftp but nothing changed....
Please help!