I was trying your MultiColumnSorting function.
In your documentation : http://www.telerik.com/help/winforms/grid_sorting-properties.html
It says to do : radGridView1.MasterGridViewTemplate.AllowMultiColumnSorting = true;
However, that property doesn't seem to exist. Instead, I found : radGridView1.MasterGridViewTemplate.SortExpressions.AllowMultiColumnSorting = true;
In your documentation : http://www.telerik.com/help/winforms/grid_sorting-properties.html
It says to do : radGridView1.MasterGridViewTemplate.AllowMultiColumnSorting = true;
However, that property doesn't seem to exist. Instead, I found : radGridView1.MasterGridViewTemplate.SortExpressions.AllowMultiColumnSorting = true;
I have RadControls for WinForms Q3 2009 SP1.