Crystal Reports locks the program that is running the report on Windows 7

We are having many clients that are running our program on Windows 7 64 bit platforms, our program that displays the report hangs our program when the user closes the report.  I ran the latest SP9 and SP10 on the workstation and it still has the problem.

Windows 7 64 bit operating system.

Windows Form Application

I have wrote a very simple application and have isolated the problem to the dispose method.

DataSet ds = newDataSet();

DataTable dt = newDataTable("FRUIT");

DataColumn dc = newDataColumn("Type");

            dt.Columns.Add(dc);

            dc = newDataColumn("Color");

            dt.Columns.Add(dc);

            DataRow dr = dt.NewRow();

            dr["Type"] = "Apple";

            dr["Color"] = "Red";

            dt.Rows.Add(dr);

            dt.AcceptChanges();

            ds.Tables.Add(dt);

CrystalReport2 RPT2 = newCrystalReport2();

            RPT2.SetDataSource(ds);

            crystalReportViewer1.ReportSource = RPT2;

if (crystalReportViewer1.ReportSource isCrystalReport2) // check if valid reference

            {

                CrystalReport2 rpt = crystalReportViewer1.ReportSource asCrystalReport2;

                rpt.Database.Tables.Dispose();//When code reaches this point, the program locks up and freezes.

                rpt.Database.Dispose();

                rpt.Dispose();

            }

            crystalReportViewer1.Dispose();

            crystalReportViewer1 = null;

            this.Close();