error when creating datetime.time with dateutil.tz.tzlocal

Creating datetime.time with dateutil.tz.tzlocal creates valid datetime.time object, but this object raises error when __str__, __repr__ or isoformat method is called on it.

Demonstration:

 >>> import datetime
 >>> import dateutil.tz
 >>> t1 = datetime.time(1, 2, tzinfo=dateutil.tz.tzutc())
 >>> t2 = datetime.time(1, 2, tzinfo=dateutil.tz.tzlocal())
 >>> t1
 datetime.time(1, 2, tzinfo=tzutc())
 >>> t2
 datetime.time(1, 2, tzinfo=tzlocal())
 >>> print t1
 01:02:00+00:00
 >>> print t2
 Traceback (most recent call last):
   File "<stdin>", line 1, in <module>
   File "/usr/lib/pymodules/python2.6/dateutil/tz.py", line 92, in utcoffset
     if self._isdst(dt):
   File "/usr/lib/pymodules/python2.6/dateutil/tz.py", line 134, in _isdst
     + dt.second)
 AttributeError: 'NoneType' object has no attribute 'toordinal'

My locale timezone is "Europe/Prague", python2.6, dateutil 1.4.1, debian linux.