ASPxGridView - How to show grouped row count summary in group row instead of actual child row counts

It doesn't work as I expected… it almost worked :-)
The problem is that GetChildRowCount only works if the group is expanded. When it is NOT expanded it returns (1) instead of the actual number of grouped rows that would be visible beneath it if it was actually expanded.
I can try to demonstrate by using the same example I've used before:
If it's expanded, it will work alright:

• New York (count = 1)
  -+ Felipe (count = 2)
• Rio (count = 2)
  -+ Felipe (count = 2)
  -+ Julio (count = 1)
  If I collapse the "Rio" group, it will look like this:
• New York (count = 1)
  -+ Felipe (count = 2)
• Rio (count = 1)
  We know, though, that there are (2) "child rows" within the Rio group.
  I've found out that this is due to the grid running in XPO ServerMode. I can't stop using server mode because this grid may display over 10.000 items, so without ServerMode pagination would be next to impossible.
  I believe ServerMode is trying to be 'too smart' and is not issuing a Count to the server, but just returning '1' if there are any records within a group (so it can add a '+' sign next to it)… Well, this is just speculation, fact is that the GetChildRow does not behave as expected when in ServerMode.
  Is there a way to make it work in server mode?

Anthony, I've attached a project which have the SAME data using 2 separate XpoDataSource objects, one in server mode, another without it, displayed in two identically configured grids… You can see that in the one without server mode the count is shown correctly, but in the other it keeps at 1 up until we expand the group, when it suddenly shows the right count.
The sample is self-explanatory… Keep in mind I didn't bother with proper XPO data layer design, so it won't even use a thread-safe data layer, but it is NOT a problem at all for this little sample :-) I know how to program it correctly for production :-)

Felipe, this event allows you to provide a custom text for each group. However, if you wish to display only the row count, it is possible to use the built-in summary functionality:

ASPx
<GroupSummary>  
    <dx:ASPxSummaryItem SummaryType="Count" FieldName="Name" ShowInColumn="Name" />  
</GroupSummary>  

I've updated the answer.

Hi Anthony,
The group summary does not what I want. It counts all individual instances of child rows inside it, while I only want the count of the grouped rows only, because I'm interested in the grouped count, not the individual count.
I'm attaching an updated project which shows this requirement, and the problem more clearly than the previous one, which, unfortunately was a little misleading because the amount of individual rows (child rows) was equal to the amount of grouped rows. In this sample they are not equal and you can see that the "MANUAL" count done in the event handler gives me the correct amount without server mode, and the group summary gives the ordinary, individual rows count, and in the server mode grid the "MANUAL" count only works after the group is expanded…
I need it to work with ServerMode too… This is a very important requirement because a new customer will only sign for our product if this works…
If it works without server mode, there should be a way to make it work with server mode. I'm not afraid of implementing some server logic at the XpoDataSource class, but I don't know which events to handle.
I also believe that this discrepancy in behavior may be a bug in server mode.

The attached project…