ComboBox not filled with DataTable - Why?

[VBobCat]

I used this code:

Friend Sub PopulateCB(ByRef mycontrol As ComboBox, _
                      ByVal expressionSQL As String)
    ' DMBD is my data-handling class:
    Using DataTableOrigem As DataTable = DMBD.Read_a_Table(expressionSQL)
        ' this MsgBox told me my Table is correctly filled:
        MsgBox(DataTableOrigem.Rows(0).Item(0).ToString)
        ' this MsgBox told me my control was correctly passed:
        MsgBox(mycontrol.Name)
        mycontrol.DataSource = DataTableOrigem
        mycontrol.ValueMember = DataTableOrigem.Columns(0).ColumnName
        mycontrol.DisplayMember = DataTableOrigem.Columns(1).ColumnName
    End Using
End Sub

Nevertheless, mycontrol remains empty after this.

Could someone help me figure out why?

Thank you very much!