For a specific reason, one of our form is using the Grid.ActiveRow property to compare its value with our form property which represents the last active row of the grid.

So, basically, we have this in the Grid.AfterRowColChange():

IF ThisForm.Grid.PreviousRow<>ThisForm.Grid.ActiveRow
   ...
ENDIF

The problem is that this is slow when having 450000 records.

It seems that the grid ActiveRow is having a weird behavior which slows down the system.