There is currently no announced date for the next patch release.
If you need to ability to fix multiple header rows during a sort, and have access to the source code, you can add the method below in the GridData.cs file where the other SortByColumn methods appear.
///
/// Sorts tha data object by the specified column.
///
/// The column that holds the key for sorting this object.
/// The sort direction: asceding or descending
/// You should pass in GridModel.Rows.HeaderCount to specify if there are additional headers
/// displayed in the grid that should not be sorted.
public void SortByColumn(int colIndex, ListSortDirection direction, int extraHeaderCount)
{
int hc = extraHeaderCount+2;
ArrayList sortArray = new ArrayList();
int count = RowCount-extraHeaderCount;
for (int n = 0; n < count; n++)
sortArray.Add(sfTable.Rows[n+hc]);
GridColumnSorter sorter = new GridColumnSorter(colIndex+1, direction, sortArray);
sortArray.Sort(sorter);
for (int n = 0; n < sortArray.Count; n++)
sfTable.Rows[n+hc] = sortArray[n];
}
