Exception While creating Crystal Reports

Hi all
I have a Problem While Creating Crystal Reports
The Exception was
The Exception is:-Exception :: System.InvalidCastException: Unable to cast object of type 'System.Data.DataTable' to type 'System.Data.DataView'.

The crystal Reports Producing code When i click the button was

try

{

System.Data.DataTable table = ((DataView)dataGridViewPOR.DataSource).Table;

POCrystalReport crystal = new POCrystalReport();

crystal.SetDataSource(table);

this.POCrystalReportViewer.ReportSource = crystal;

}
The Exception Raised in the highlighted line .I used this code many times.but exception raisweed this time
please solve my issue.

NagaRaju T