>The weird thing, Antonio, is that if I use Ctrl+Tab on the keyboard to give focus back to grid1 it updates perfectly - it just freaks out when you call the AfterRowColChange from the LostFocus of the date fields in grid2.
>As I said earlier, I have had trouble before trying to access DynamicForecolor from anywhere other than in the grid itself.

Perhaps you've got a situation where the expression in question contains a reference to a table column -- one that won't be available if a different workarea is selected?