ADO filter results do not show up correctly in DBCombo

I have 2 tables AREA and AREA_DETAIL and a form with two DBCombos bound to the tables. In the form_load routine I open the both tables and bind dbcArea. In the dbcArea_Change event, I filter the records from AREA_DETAIL to only show the records associated with the Area selected in dbcArea. The recordset refreshes properly when the user clicks dbcArea, but the results shown in dbcArea_Detail are wrong: every record from the table AREA_DETAIL appears in the list.

Code:

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Private Sub Form_Load()

rsAreas.Open "Select IdAREA, AREA From AREAS Order By AREA", cnSICC, adOpenKeyset, adLockOptimistic

rsAreas_Detail.Open "Select IdDETAIL, IdAREA, DETAIL From Areas_Detail Order By DETAIL", cnSICC, adOpenKeyset, adLockOptimistic

If rsAreas.RecordCount <> 0 Then
    With dbcArea
        Set .RowSource = rsAreas
        .ListField = "AREA"
        .BoundColumn = "IdAREA"
        Set .DataSource = Adodc1
        .DataField = "IdAREA"
    End With
Else
    MsgBox "Areas have not yet been added to the database.", vbExclamation
    Unload Me
End If

End Sub

Private Sub dbcArea_Change()

If dbcArea = "" Then Exit Sub

rsAsignaturas.Filter = "IdAREA = " & dbcArea.BoundText

If rsAreas_Detail.RecordCount = 0 Then
    MsgBox "No details exist for the area " & dbcArea & ".", vbExclamation
    Set dbcAreas_Details.RowSource = Nothing
Else
    With dbcAreas_Details
        Set .RowSource = rsAreas_Details
        .ListField = "DETAIL"
        .BoundColumn = "IdDETAIL"
        .DataField = "IdDETAIL"
  End With
End If

End Sub

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I have tried binding dbcAreas_Details in the Form_Load event and refilling and refreshing it at various points, all to no avail. I can do what I need to do by closing the recordset and reopening it each time dbcArea is clicked, but that is very inefficient.

Help?

Thanks

Andrew