FTP 503 ERROR

[support2]

I don't really understand why you send the second USER command ... could you explain and post a log file at the debug level?

Sorry apparently we're not sending the USER edtFTP is
As I said, the whole thing works for a lot of sites, but not the one in question.
FTPReply reply = control.SendCommand("USER " + user);

Here's the log entry

INFO SNP_CONNECTION_PARAMS Logging in
INFOExpected reply codes = [230,331]
INFO Bad sequence of commands. (code=503) : EnterpriseDT.Net.Ftp.FTPException: Bad sequence of commands. (code=503)
EnterpriseDT.Net.Ftp.FTPException: Bad sequence of commands. (code=503)
at EnterpriseDT.Net.Ftp.FTPControlSocket.ValidateReply(FTPReply reply, String[] expectedReplyCodes) in C:\Projects\BNYM.APT.DPP.FTP.root\BNYM.APT.DPP.FTP\edtftpnet-1.2.6\src\net\ftp\FTPControlSocket.cs:line 889
at EnterpriseDT.Net.Ftp.FTPClient.Login(String user, String password) in C:\Projects\BNYM.APT.DPP.FTP.root\BNYM.APT.DPP.FTP\edtftpnet-1.2.6\src\net\ftp\FTPClient.cs:line 1454
at BNYM.APT.DPP.FTP.FTPOperation.Execute(String configsectionlabel) in C:\Projects\BNYM.APT.DPP.FTP.root\BNYM.APT.DPP.FTP\BNYM.APT.DPP.FTP\BNYM.APT.DPP.FTP\FTPOperation.cs:line 52
INFO SNP_CONNECTION_PARAMS starting 5/5/2011 7:33:06 AM
INFO SNP_CONNECTION_PARAMS Logging in
INFOExpected reply codes = [230,331]
INFO Bad sequence of commands. (code=503) : EnterpriseDT.Net.Ftp.FTPException: Bad sequence of commands. (code=503)
EnterpriseDT.Net.Ftp.FTPException: Bad sequence of commands. (code=503)