Android, HttpPost working with ip, not with url

1. HttpClient client = new DefaultHttpClient();
2. HttpPost httpPost = new HttpPost("http://simonexxx.no-ip.info/ilMercatinoDelxxx/ModificaArticolo?id=" + id);
3. //HttpPost httpPost = new HttpPost("http://151.xx.xx.247:8080/ilMercatinoDelxxx/ModificaArticolo?id=" + id);
4.        
5. HttpPost httpPost = new HttpPost("http://simonexxx.no-ip.info:8080/ilMercatinoDelxxx/ModificaArticolo?id=" + id);