I'm coming back to this again now after trying a couple things after Mike's first reply and not getting it figured out.  I had tried many different values and combinations of values in the SummaryDisplayArea but none got what I needed. I just worked out a way of getting the sum I want in the Band(0) summary row but like I mention below, it seems like overkill and it has other drawbacks, especially since I need to do this for a lot of columns.  And before I go doing that method, I wanted to make sure I wasn't missing something.

While I'm at it, below is graphically what I need in case my original post wasn't clear enough.  I need a grand total at the very bottom of the grid for a number that is in the child rows.  I can get a total for a column in the parent: easy.  I can get sub totals for the child column for each individual parent in the island summary: again easy.  But I can't get the grand total for that child column for all parents.  (I've got 3 datatables, 1 is the parent and the other 2 are children of that, it's one to many between the parent and each child, with the parent in Bands(0), and the children in Bands(1) and Bands(2))

ParentA                                                 5
  ChildA.1               10
  ChildA.2                 7
  (Child Summary)    17
ParentB                                                 8
  ChildB.1                 6
  ChildB.2                 9
  (Child Summary)    15
 (Parent summary)                                  13
                               ^ (need this grand total but can't get it to work)
                    
Want parent summary to look like this:                   
(Parent summary)    32                             13
 

Below is a snippet of what I've been testing with.  See my comments.

Is there a way to make the spots marked *A* or *B* work the way I describe?
See the spot I marked with *C*: that is a way that gets the number I want in the Band(0) summary row but like I mentioned doesn't seem like the right way to do it:


    Private Sub ugrdMain_InitializeLayout(ByVal sender As System.Object, ByVal e As Infragistics.Win.UltraWinGrid.InitializeLayoutEventArgs) Handles ugrdMain.InitializeLayout

        If e.Layout.Bands(0).Summaries.Count = 0 Then

            Dim columnToSummarize As UltraGridColumn
            Dim summary As SummarySettings

            '' Summary in the parent of a column in the parent works fine
            columnToSummarize = e.Layout.Bands(0).Columns("ContractQuantity")
            summary = e.Layout.Bands(0).Summaries.Add("Total_ContractQuantity", SummaryType.Sum, columnToSummarize, SummaryPosition.UseSummaryPositionColumn)

            '' Summary in the child of a column in the child works fine too
            columnToSummarize = e.Layout.Bands(2).Columns("DisplayUSDOutOfRange")
            summary = e.Layout.Bands(2).Summaries.Add("TotalUSDOutOfRange", SummaryType.Sum, columnToSummarize, SummaryPosition.UseSummaryPositionColumn)

            '' Can't get summary in the parent's grand totals of a column in the child though:

            '' *A* This doesn't work, column from band 2 summarized in 0:
            'columnToSummarize = e.Layout.Bands(2).Columns("DisplayUSDOutOfRange")
            'summary = e.Layout.Bands(0).Summaries.Add("Total_DisplayUSDOutOfRange", SummaryType.Sum, columnToSummarize, SummaryPosition.UseSummaryPositionColumn)

            '' *B* This doesn't work, tried referencing the child column but through the parent band using a relative reference
            ' I got errors on the variations I tried: this method might work but I just got the format wrong
            'columnToSummarize = e.Layout.Bands(0).Columns("headers_psparforecastingmonthclose3/displayusdoutofrange")
            'summary = e.Layout.Bands(0).Summaries.Add("GrandTotal_DisplayUSDOutOfRange", SummaryType.Sum, columnToSummarize, SummaryPosition.UseSummaryPositionColumn)

            '' *C* If I add an extra unbound column in the parent (Bands(0)) with a formula that sums the child column:
            '' sum([../headers_psparforecastingmonthclose3/displayusdoutofrange])
            '' it kind of works but I have to keep that column showing in the parent for the summary to show (which I'd rather not have)
            '' and since I was using SummaryPosition.UseSummaryPositionColumn, it is displaying under the Unbound column, not under the child column it is summarizing
            '' The child band is wider than the parent so I can't do something like this to reposition it since there isn't a parent column to position it under:
            ''summary.SummaryPositionColumn = columnToPositionUnder
            '' I need to do this for like 26 columns too: adding 26 unbound formula columns in the parent and 26 summaries just to summarize columns
            '' in the child seems like overkill, not to mention inefficient and potentially slow performance-wise
            'columnToSummarize = e.Layout.Bands(0).Columns("UnboundColumn1")
            'summary = e.Layout.Bands(0).Summaries.Add("Total_UnboundColumn1", SummaryType.Sum, columnToSummarize, SummaryPosition.UseSummaryPositionColumn)

            '' have tried several different individual values for this and different combinations of the values but that didn't get anywhere either
            e.Layout.Override.SummaryDisplayArea = SummaryDisplayAreas.BottomFixed Or SummaryDisplayAreas.GroupByRowsFooter Or SummaryDisplayAreas.InGroupByRows Or SummaryDisplayAreas.RootRowsFootersOnly
            e.Layout.Override.GroupBySummaryDisplayStyle = GroupBySummaryDisplayStyle.SummaryCells

        End If
           
     End Sub
    
    
This is kind of how my work around looks with the 17 and 15 in the parent row being the calulated unbound column which then gets summarized in the parent summary with 32 in that same position...
    
ParentA                                                 5                    17
  ChildA.1               10
  ChildA.2                 7
  (Child Summary)    17
ParentB                                                 8                    15
  ChildB.1                 6
  ChildB.2                 9
  (Child Summary)    15
 (Parent summary)                                  13                   32
                               
Thanks,
Andy    

PS  Sorry that code seems hard to read: are there formatting switches/tags to use in these forums for puting code in a fixed width font box separate from the rest of the post text like I've seen in other forums?  I looked and didn't find anything.  Even looked at communityserver.org but didn't see anything there either.