I'm having trouble reproducing the problem, Germán. Running with Python 3.3.2 from a couple of days ago:

Python 3.3.2+ (3.3:0eef1670f316, Sep  8 2013, 08:31:59) 
[GCC 4.6.3] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> from xml.etree.ElementTree import *
>>> e = ElementTree().parse('houses.xml')
>>> e.iter()
<_elementtree._element_iterator object at 0x7fac621d9aa0>
>>> list(e.iter())
[<Element '{http://dogs.house.local}group' at 0x7fac621e02b8>, <Element '{http://dogs.house.local}house' at 0x7fac621e0368>, <Element '{http://dogs.house.local}id' at 0x7fac621e0418>, <Element '{http://dogs.house.local}dogs' at 0x7fac621e0470>, <Element '{http://dogs.house.local}house' at 0x7fac621e04c8>, <Element '{http://dogs.house.local}id' at 0x7fac621e0520>, <Element '{http://dogs.house.local}dogs' at 0x7fac621e0578>]



Can you provide a patch for the ET tests that I can apply to tip of 3.3 and see this reproduced?