Datagrid in User control not Sorting

[VBBoy]

Hello..
I had created a user web control which uses datagrid at its center and
adds some functionality which i need in a project. One of the
functionality is Sorting the data on column click. i had done every
thing possible but it is not working. The fact is if i enable
AutoGeneration of columns then it is working. But if i add bound
columns manually then it is executing the concerned sort method.
If i use a simple datagrid in a web page with what ever combination
then it is working properly
Can some body help?

Thanks in Advance
Hemant