$ python
Python 2.7.2+ (default, Aug 16 2011, 09:23:59) 
[GCC 4.6.1] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import notmuch
>>> db = notmuch.Database()
>>> q = db.create_query("id:test20110928121705.GA3877@example.com")
>>> t = q.search_threads()
>>> for a in t:
...     print a
... 
Traceback (most recent call last):
  File "<stdin>", line 2, in <module>
  File "/usr/local/lib/python2.7/dist-packages/notmuch/thread.py", line 379, in __str__
    thread['subject'] = self.get_subject()
  File "/usr/local/lib/python2.7/dist-packages/notmuch/thread.py", line 311, in get_subject
    return subject.decode('UTF-8')
  File "/usr/lib/python2.7/encodings/utf_8.py", line 16, in decode
    return codecs.utf_8_decode(input, errors, True)
UnicodeDecodeError: 'utf8' codec can't decode byte 0xe8 in position 6: invalid continuation byte
>>>