I have RadGrid with RadButton as Checkbox inside it for selection.

This code: 
For Each item As GridItem In PrimaociGrid.MasterTableView.Items
            Dim cb As RadButton = CType(item.FindControl("PrimaPorukuCheckBox"), RadButton)
            cb.Checked = True
Next

worked in 2012.3.1016.40

With new 2013 q2 this is not working
I try 2013.2.709.40, same , not working 
There in no check in check box