Basic - porblemas con mshflexgrid

tengo problemas al mostrar una tabla mshflexgrid,
mi objeto se llama mostrar
Public rct As Recordset
Private Sub cmdSalir_Click()
Unload Me
End Sub

Private Sub Form_Load()
Set Me.rct = New ADODB.Recordset
Me.rct.Open "select *from Personal", cnn, adOpenDynamic, adLockOptimistic
cargar
End Sub
Private Sub cargar()
Me.Mostrar.DataSource = Me.rct
End Sub

la coneccion la realizo por un modulo

Public cnn As ADODB.Connection
Public Sub Main()
Presentacion.Show
End Sub
Public Function cargar() As Boolean
On Error GoTo errores
Set cnn = New ADODB.Connection
With cnn
.ConnectionString = "Provider=SQLOLEDB.1;Integrated Security=SSPI;Persist Security Info=False;Initial Catalog=Mantenimiento;Data Source=."
.CursorLocation = adUseClient
.Open
End With
cargar = True
errores:
If Err.Number <> 0 Then cargar = False
End Function
Public Function cerrar()
On Error GoTo resumen
With cnn
If .State = 1 Then .Close
Set cnn = Nothing
End With
End Function

ayudenme es la una funcion que no me funciona