Windows DataGrid Problem,... "BUG"??

[Bernardo]

I'm making a windows project...
I have a datagrid with one checkbox collumn.
When I check the checkbox (sometimes) the grid redraws and
stays white with a Red X in the middle and the application
freze...
I think I have to make a datagrid "refresh" before and
after de check...

Here is the code
************************************************** *******
bool bEstado;
DataGrid.HitTestInfo hti = dtgPerfilModulo.HitTest(e.X,
e.Y);

try
{
if(hti.Column == 1 && hti.Type ==
System.Windows.Forms.DataGrid.HitTestType.Cell)
{

//Cahnge the state
bEstado=(bool)dtgPerfilModulo[hti.Row,hti.Column];
dtgPerfilModulo[hti.Row,hti.Column] =! bEstado;

//This don't do anything, I tryied without this line to!
dtgPerfilModulo.Update();
}
************************************************** ********

Thanks for your help,
BP