Problema passaggio parametri ad un report da web

...
LocalReport report = this.reportViewer1.LocalReport;

ReportParameter parametro = new ReportParameter("nomeParametro", "valore");
report.SetParameters(new ReportParameter[] { parametro }); 

this.reportViewer1.RefreshReport();
...

reportViewer1.ServerReport.SetParameters(...

LocalReport mioreport = reportViewer1.LocalReport;
mioreport.ReportPath = "c:\\.......\\mioreport.rdlc";

Warning[] warnings;
string[] streamids;
string mimeType;
string encoding;
string filenameExtension;

byte[] bytes = mioreport.Render(
            "Pdf", null, out mimeType, out encoding, 
            out filenameExtension,
            out streamids, out warnings);

using (FileStream fs = new FileStream("c:\\mioreport.pdf", FileMode.Create))
{
    fs.Write(bytes, 0, bytes.Length);
}
...