Hi David,

I took a look at this and it looks like a bug to me. You should be able to change the e.SortedColumns inside the BeforeSortChange event and have this affect the sorting, but it does not work.

The code would look like this:

        private void ultraGrid1_BeforeSortChange(object sender, BeforeSortChangeEventArgs e)
        {
            UltraGridBand band = e.Band;            

            // Examine the columns that are currently sorted.
            foreach (UltraGridColumn originalColumn in band.SortedColumns)
            {
                // Look for grouped columns.
                if (originalColumn.IsGroupByColumn)
                {
                    // Get the new sorted column.
                    UltraGridColumn newSortedColumn = e.SortedColumns.Exists(originalColumn.Key) ? e.SortedColumns[originalColumn.Key] : null;

                    // If the column was originally grouped, but does not exist in the
                    // e.SortedColumns, it means it is no longer grouped or sorted.
                    if (newSortedColumn == null)
                    {
                        // Add the columm back in so it stays sorted and is just
                        // un-grouped.
                        bool descending = originalColumn.SortIndicator == SortIndicator.Descending;
                        e.SortedColumns.Add(originalColumn.Key, descending);
                    }                    
                }
            }
        }

Hm, that's odd. I can't see why the column would no longer be sorted. That might be a bug, but it might be the intended behavior for some reason. In any case, it's probably not something that we could change at this point without potentially breaking  existing applications.