can't find body tag

[Henrik Nordvik]

url = 'http://authorize.tv.com/1324-4-90.html'
a = urllib2.urlopen(url).read()
doc = lxml.html.fromstring(a)

fails with
TypeError: object of type 'NoneType' has no len()
on line 636 in /usr/lib/python2.6/dist-packages/lxml/html/__init__.py
on ubuntu 10.10

Python : (2, 6, 6, 'final', 0)
lxml.etree : (2, 2, 6, 0)
libxml used : (2, 7, 7)
libxml compiled : (2, 7, 6)
libxslt used : (1, 1, 26)
libxslt compiled : (1, 1, 26)