I seem to be having a problem with the FTPWebRequest. I get an error (see below code) when it executes the emboldened line. Any ideas?

Code:
Dim uploadRequest As FtpWebRequest = WebRequest.Create(uploadUrl)
uploadRequest.Method = WebRequestMethods.Ftp.UploadFile

If strUserName <> "" And strPassword <> "" Then
       uploadRequest.Credentials = New System.Net.NetworkCredential(strUserName, strPassword)
End If

uploadRequest.EnableSsl = blnSecure
uploadRequest.KeepAlive = True
uploadRequest.UsePassive = blnPassive
uploadRequest.Proxy = Nothing

RequestStream = uploadRequest.GetRequestStream()
fileStream = File.Open(fileName, FileMode.Open)

Dim buffer(1024) As Byte
Dim bytesRead As Integer
While True
        bytesRead = fileStream.Read(buffer, 0, buffer.Length)
        If bytesRead = 0 Then
            Exit While
        End If
        requestStream.Write(buffer, 0, bytesRead)
End While

' The request stream must be closed before getting the response.
requestStream.Close()

uploadResponse = uploadRequest.GetResponse()
"The server returned an address in response to the PASV command that is different than the address to which the FTP connection was made."