Saved stream 3 times the size of the read stream?

using (Stream istream = conn.OpenRead(Path.Combine(this.RemoteDir, this.RemoteFile)))
{
    // set up output stream & file
    Stream ostream = File.Create(localfilename, (int) istream.Length);

    try
    {

        // init progress                            
        this.InitProgress(this.RemoteFile, istream.Length);

        // set up read buffer
        byte[] buf = new byte[8192];
        int read = 0;

        // read file
        while ((read = istream.Read(buf, 0, buf.Length)) > 0)
        {
            // write to local file
            ostream.Write(buf,0,buf.Length);

            // update progress
            this.pos = istream.Position;
            this.pgbar.UpdateProgress(this.pos);
        }

    }
    catch(Exception e)
    {
        this.Status.OK = false;
        this.Status.Msg = e.Message;
    }
    finally
    {
        istream.Close();
        ostream.Close();
    }
}