DataGridView checkbox click calls DatagridView.CommitEdt() three times, why?

hi friends,

please refer to my you tube video to see a video capture of what im talking about : )

I have a simple app with a datagridview with a checkbox column. I want to check the check/uncheck status of cell so that I can color the cell if it's checked.

I have use the CurrentCellDirtyStateChange() and CellValueChange()... what I don't understand when I simply check a checkbox why the control calls the DataGrdview.CommitEdit(...) three times?

thanks

I use Visual studio 2012 Ultimate and SQL server 2008 developer edition!