IE SSL

http://support.microsoft.com/kb/316431

Internet Explorer is unable to open Office documents from an SSL Web site

trecho de código para exportar e abrir planilha XLS

                    Response.Buffer = true;

                    Response.ClearHeaders(); // Required due an issue on IE using SSL. 

                    Response.AddHeader("content-disposition", "attachment;filename=XXX.xls");

                    Response.ContentType = "application/vnd.ms-excel";

                    Response.Charset = "";

                    this.EnableViewState = false;

                    StringWriter oStringWriter = new StringWriter();

                    HtmlTextWriter oHtmlTextWriter = new HtmlTextWriter(oStringWriter);

                    HtmlForm frm = new HtmlForm();

                    this.Controls.Add(frm);

                    frm.Controls.Clear();

                    frm.Controls.Add(gvReportExport);

                    frm.RenderControl(oHtmlTextWriter);

                    Response.Write(oStringWriter.ToString());

                    Response.Flush();

                    Response.End();