No coinciden los tipos de datos en la expresión de

Hola tengo este código y me da error que no coinciden los tipos de datos en la expresión de criterios
Private Sub Command()
For i = 1 To MS.Rows - 1
MS.Col = 1
variable1 = MS.TextMatrix(i, 1)
MS.Col = 2
variable2 = MS.TextMatrix(i, 2)
MS.Col = 3
variable3 = MS.TextMatrix(i, 3)
asoc.Execute ("insert into tabla (v1,v2,v3) values (" & "'" & variable1 & "','" & variable2 & "','" & variable3 & "')")
Next i
MS.Clear
MS.Rows = 1
Set rr = asoc.Execute("select v1,v2, Sum(v3) AS [Suma] from tabla group by v1,v2 order by sum(v3) desc") 'aka esta el error
MS.TextMatrix(0, 1) = "Codigo"
MS.TextMatrix(0, 2) = "Producto"
MS.TextMatrix(0, 3) = "Monto"
fil = 1
Do While Not rr.EOF
MS.Rows = MS.Rows + 1
MS.TextMatrix(MS.Rows - 1, 1) = rr!v1
MS.TextMatrix(MS.Rows - 1, 2) = rr!v2
MS.TextMatrix(MS.Rows - 1, 3) = rr![suma]
rr.MoveNext
fil = fil + 1
Loop
asoc.Execute ("delete from tabla")
End Sub