I had same problems with delete command on hierarchical grid. I think the problem it's caused by different declaration between DataKeyNames in grid and DeleteParameters in SqlDataSource.
Here is my code
The stored procedure called to delete the row of first child grid is this
but, as you can see, DataKeyNames in first child grid are VersamentoId,ConsumoID. This is done because VersamentoId is the correlation key with parent grid and ConsumoId is the correlation key with another child grid.
When I try to delete a row of first child grid, system return the following error
Anyone knows a solution to bring together hierarchical grids and delete of child rows?
Thanks a lot