My Sort order of records is persisting in normal radgrid but when i am using radgrid with grouping its not persisting.

The ragGrid during page load are as folllows.

Customer group Name        Customer Name      Sort Order
Group 1
                                              Very High                    1
                                                High                          2
                                               ABC                           3

and the filer for columns format are as follow

<telerik:GridBoundColumn HeaderText="Customer Name" FilterControlAltText="Filter column1 column"
                                    DataField="Name" UniqueName="Name" FilterControlWidth="150px" AutoPostBackOnFilter="true"
                                    HtmlEncode="true" CurrentFilterFunction="Contains" ShowFilterIcon="false">
                                </telerik:GridBoundColumn>

And when i filter the grid on customer name with "high" word the grid shows results as follow

Customer group Name        Customer Name      Sort Order
Group 1
                                                  High                        2
                                              Very  High                   1
                                               
And i am needdatasource event then also this problem occurring so please provide me any solution.