Clear Selection On Grid

I have a grid and when a user selects a block of cells and then hides one or more columns, I would like to clear the selected cells on the grid. I am calling grid.clearSelection() but it is not working. What else do I have to do?



Thanks.

Can be forced by
mygrid._HideSelection();

What is the purpose of grid.clearSelection()? 

clearSelection() removes selection of the grid which made by selection a row with mouse click or with API (selectRow())