Not able to export to excel using IE8

Hi

I am getting the below error when exporting data  to excel from telerik grid(created a user control and using that) only in ie8 for https site.


I am using the below code for export functionality

     Response.ContentType = "text/csv";
     Response.AddHeader("content-disposition", "attachment; filename=filename.csv");
      Response.Write(csv);
     Response.End();

Note:cvs is a string builder which contains the data to export.

Please help me to resolve the issue.