Adding the mapping name makes your code work for me in
this sample.
One other thing to check is exactly what is stored in your database in this column. If it is not a boolean, but instead something like a Y or N, or 1 or 0, then you should change the GridCheckBoxCellInfo to reflect the actual values your datasource has. (To see these actual values, run the project commenting out the line that sets the CellType so the value just shows in the cells).