Populating a textbox in a sub report using VBA | Access forum

Dear Best STL

I have a report containing a subreport
The subreport grows if there are records in its 'Detail' section and shrinks to nothing when there is nothing to display - this works fine.
I want to add a title/header in the Report Header section of the subreport and populate it using VBA - I have to use VBA as I'm dealing with two languages.
I've created a Sub to do this and a reference to the Sub within the subreport's Activate event:

Sub popSubTTL()
[TextBox_my] = "my text"
End Sub

Private Sub Report_Activate()
popSubTTL
End Sub

If I open the subreport in isolation the TextBox populates fine.
If I open the main report, the records in the detail section show as they should, but the TextBox doesn't populate!
When I add a breakpoint to the above Subs, and open the main form, the above functions are completely skipped (can't even step through them) and the textbox doesn't get populated.
If I delete the Report_Activate() Sub but target the popSubTTL() from the main form, the code stops at the breakpoint and all looks as if it should work ok - the text box is assigned the text as when I rollover the [TextBox_my] part of the code I see it has the value of "my text", but the textbox just doesn't get populated!
I haven't any more ideas of how to populate this TextBox! It should be the easiest thing to do and works everywhere else, but not on this subreport.

Your help is much appreciated!
Joe