Hello Mark.
FWIW, I have not been able to get a dropdown COMBO to work correctly in a grid. I have only been able to get a dropdown LIST to work in the grid.< ahem > In that case you need to check out chapter 6 of
1001 Things You Wanted to Know About VFP because there is a combo class that lets you add items to its RowSource on the fly while in a grid. I also wrote an article for Advisor about this technique in February of 2000 < s >