Hi Chad,
Please try setting the CheckBoxOptions property for the checkboxcolumn in the grid, see if this helps.
grid.Binder.InternalColumns["CheckBoxColumn"].StyleInfo.CellType = "CheckBox";
grid.Binder.InternalColumns["CheckBoxColumn"].StyleInfo.CheckBoxOptions = new GridCheckBoxCellInfo("1", "0", DBNull.Value.ToString(), true);
Please refer to the forum thread below,
http://www.syncfusion.com/Support/Forums/message.aspx?MessageID=18606
Refer to KnowledgeBase(KB) article below, for the details on CheckBoxOptions property.
http://www.syncfusion.com/support/kb/grid/Default.aspx?ToDo=view&questId=28
Let us know if you need any further assistance.
Regards,
Rajagopal