What am I doing wrong with urllib.urlopen() ?

[Jose Rivera]

The URL calculated :
 
 http://avisos.elnorte.com/casa_venta_result.asp?fotos=0&Order=order+by+colonia&Precio_i=-1&Presentacion=Tabla&Precio_f=-1&PLANTAS=0&pagina=1&id_inmueble=3&dia=&RECAMARAS=0&constr_f=-1&COLONIA=0&BANOS=0&Tipo=CASAS&Constr_i=-1&Terreno_i=-1&Terreno_f=-1&zona=0
 
 works on my PC, but:

The first time it gives me the error that you said, but a click on the
http address of iExplorer and an enter on the keyboard load
succesfully the page.

I hope that help to find the problem...