Excel - Error en ejecucion de macros

Sub actTC()

    Dim xml, HtmlDoc, Tbl, i, Q%, j%, R%

    ...

    For Each i In xml

        If i.className = "class=""form-table""" Then Exit For

    Next

    Set Tbl = i.Rows

   ...

End sub

Sub actTC()

    Dim xml, HtmlDoc, Tbl, i, a, Q%, j%, R%

   ...

    For Each i In xml

        If i.className = "class=""form-table""" Then Set a=i: Exit For

    Next

    Set Tbl = a.Rows

   ...

End Sub

Sub actTC()

    Dim xml, HtmlDoc, Tbl, i, Guarda, Q%, j%, R%

    Dim l_Obj As ListObject

    Dim mm%, yy%, nextTime!

    Application.ScreenUpdating = False

    mm = Month(Range("f_Ref")): yy = Year(Range("f_Ref"))

    Set l_Obj = ActiveSheet.ListObjects(1)

    If Not l_Obj.DataBodyRange Is Nothing Then l_Obj.DataBodyRange.Delete

    Set xml = CreateObject("Microsoft.xmlHttp")

    nextTime = 0.5 + Timer: While Timer < nextTime: DoEvents: Wend

    xml.Open "POST", "http://ww1.sunat.gob.pe/cl-at-ittipcam/tcS01Alias", False

    xml.setRequestHeader "Content-Type", "application/x-www-form-urlencoded"

    xml.Send "mes=" & mm & "&anho=" & yy

    nextTime = 0.5 + Timer: While Timer < nextTime: DoEvents: Wend

    Set HtmlDoc = CreateObject("HTMLFile")

    HtmlDoc.body.innerHTML = xml.responseText

    Set xml = HtmlDoc.getElementsByTagName("table")

    For Each i In xml

        If i.className = "class=""form-table""" Then

           Set Guarda = i: Exit For

        End If

    Next

    Set Tbl = Guarda.Rows

    Q = Tbl.Length - 1