Yes, sparse is properly set. The peculiarity here is that the caption changes from Yes to No just as it is supposed to do when the field's value changes from T to F but it doesn't stop there. The change eventually propagates to every other row in the grid, regardless of the underlying data value. I know that sounds bizarre but there are at least 8 different ways to produce this result, it's just too bad that's not what I want. Somehow, the value isn't being evaluated at the "cell" level but at the column level.