Smallbusniss Back office server 4.5

My problem is that my clients can’t ftp thier documentes.In the poxy consle -Web proxy/permissions I found that they have ftp permission (enable access control to …FTP Read).
I look to theWinSockProxy/Properties/Permissions I found the folowing:Enable access controle to ..protocol..(Unlimited access),and to FTP protocol ..to alle the user of my domein.
From the server self I can ftp.from other pc I can’t ftp even I logged as administrator.
What is wrong How can I give my domain users access to perform ftp programma’s.to send thier works to the other sites.