C# - StreamReader.ReadLine does not work properly!

Simply I have been trying to implement what BufferedStreamReader does in Java. I have a socket stream open and just want to read it in a line-oriented fashion - line by line.

I have the following server-code.

while (continueProcess)
        {
            try
            {
                StreamReader reader = new StreamReader(Socket.GetStream(), Encoding.UTF8);
                string command = reader.ReadLine();
                if (command == null)
                    break;

                OnClientExecute(command);
            }
            catch (Exception e)
            {
                Console.WriteLine(e.ToString());
            }
        }

And the following client-code:

TcpClient tcpClient = new TcpClient();
        try
        {
            tcpClient.Connect("localhost", serverPort);
            StreamWriter writer = new StreamWriter(tcpClient.GetStream(), Encoding.UTF8);
            writer.AutoFlush = true;
            writer.WriteLine("login>user,pass");
            writer.WriteLine("print>param1,param2,param3");
        }
        catch (Exception e)
        {
            Console.WriteLine(e.ToString());
        }
        finally
        {
            tcpClient.Close();
        }

The server reads only the very first line (login>user,pass) and then ReadLine returns null!

What's the easiest way of achieving this line-oriented reader as it is in Java's BufferedStreamReader? :s