Erro em msxml3.dll ao fazer POST

Estou tentando criar um POST mas ocorre o erro msxml3.dll erro '80070005' Acesso negado.

<%@LANGUAGE="VBSCRIPT" CODEPAGE="65001"%>
<%
Option Explicit

Dim data, httpRequest, postResponse

data = "var1=somevalue"
data = data & "&var2=someothervalue"
data = data & "&var3=someothervalue"

Set httpRequest = Server.CreateObject("MSXML2.ServerXMLHTTP")
httpRequest.Open "POST", "http://www.site.com.br/integracao/vagas/inscricoes/input/", False
httpRequest.SetRequestHeader "Content-Type", "application/x-www-form-urlencoded"
httpRequest.Send data

postResponse = httpRequest.ResponseText

Response.Write postResponse ' or do something else with it

%>

Como resolvo??