Custom Control inheriting from DataGrid - SortCommand, PageIndexChanged not working

[Ole]

Hi everybody,
i have a custom control that inherits from
System.Web.UI.WebControls.DataGrid.
I added filtering functionality. The problem i have is as follows:

the control ( FilterGrid ) is used in a aspx page. The Control is
created
when the user presses a button ( lets say "btn_productlist" ). When
this
button ( System.Web.UI.WebControls.Button ) is pressed, the FilterGrid
is
displayed as expected.



But as the default, as well as the additional filter functionalities
are used
( pressed, e.g. a click on a header cell / link to sort the grid ),
the FilterGrid is not shown anymore.

When the user then presses the button "btn_productlist" again, the
FilterGrid
shows up again, sorted !

How is it possible to solve this problem ? EventBubbling ?

Thanks in advance,

Ole Viaud-Murat.