Detect boolean cell change in DataGridView object

[Brian]

I have a DataGridView object that has a data table as its data source.
One of the columns of that data is boolean so the DataGridView object
shows that column as check boxes. I've been trying to detect when one
of those checkboxes changes from true to false or from false to true.
I can't seem to do that with the Events made available with
DataGridView object. I want an event that is triggered after the value
in my data table has been changed, not before. Basically, I'm counting
the number of check marks that are in that column. I've tried a number
of the Events with no luck. A few that I thought would have worked
are:

CellEndEdit
CellMouseUp
CellValueChanged

I also tried to commit the edit at the beginning of my CellEndEdit
function and then count the number of checkmarks but that still comes
up with one checkmark more or less than what is actually there. This
happens because I'm counting the old data table before the edit took
place.

Brian