Hi Bryan.

I have a grid with a combobox in one of the columns.

My problem seems to be in getting the unselected rows to behave
properly.

I gave a session some years back called "How to put a combo box in a grid". The white paper and the code samples are available on my web site. If you grab those, they should help you solve your problem without having to set sparse to false (which I think makes the grid look cluttered and busy).