error en pytho2.6-Ubuntu 11.10

Checking for installed Python... got it!
Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "/home/tony/blender/.blender/scripts/yafaray_ui.py", line 94, in <module>
    import yaf_export
  File "/usr/share/yafaray/blender/yaf_export.py", line 15, in <module>
    import tempfile
  File "/usr/lib/python2.6/tempfile.py", line 34, in <module>
    from random import Random as _Random
  File "/usr/lib/python2.6/random.py", line 47, in <module>
    from os import urandom as _urandom
ImportError: cannot import name urandom