>I just tried Kevin's code without any problem (see my post to him) and it looks as if the column holding the bool value does, in fact, default to using a DataGridViewCheckBoxColumn (with DataGridViewCheckBoxCell as the CellTemplate)

Yeah Viv, I should keep my big mouth shut when it comes to Grids. I haven't used them in quite some time and even when I did, it was only for playing with them very briefly, so I just don't know them like the back of my hand as I do with other controls.

>So I don't know why Kevin's code isn't working unless
>(a) he's made inappropriate changes to the DataGridView in the designer or
>(b) it's related to when the _AddRow() method is called

I tried the code and it worked fine for me too. At first I thought it might be, as you said, related to when the method is called because some things work better called from the load vs the constructor. So I messed around with variations of that, but still couldn't get it to NOT work.

So, Kevin ... I think we need to see more code, like the grid-specific code.

~~Bonnie