ho risolto il problema disabilitando temporaneamente il proxy durante la chiamata. di seguito riporto un esempio di funzione che restituisce la data di un file presente su un server ftp. L'ho provata a nche con proxy attivo e non da nessun problema ublic Function GET_FTP_Filedate(ByVal UserName As String, _ ByVal Password As String, _ ByVal Host As String, _ ByVal Path As String, _ ByVal Name As String _ ) As String FTP_Request = CType(WebRequest.Create("ftp://" + Host + Path + "/" + Name), FtpWebRequest) FTP_Request.Credentials = New NetworkCredential(UserName, Password) FTP_Request.Method = WebRequestMethods.Ftp.GetDateTimestamp FTP_Request.Proxy = Nothing Try FTP_Response = CType(FTP_Request.GetResponse(), FtpWebResponse) Dim Response As FtpWebResponse = FTP_Request.GetResponse Dim reader As StreamReader = New StreamReader(Response.GetResponseStream) Return Response.LastModified Catch ex As WebException Return "ERRORE FTP " & CType(ex.Response, FtpWebResponse).StatusDescription GoTo ERR_FTP End Try ERR_FTP: FTP_Response.Close() End Function