The issue is present in Python 3.0 and 2.5 as well.

Python 2.5.1 (r251:54863, Jul 17 2008, 13:21:31)
[GCC 4.3.1 20080708 (Red Hat 4.3.1-4)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import datetime
>>> t0=datetime.datetime(1,1,1)
>>> d1,d2,d3=map(datetime.timedelta, range(1,4))
>>> t0-d1
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
OverflowError: date value out of range
>>> t0-d2
datetime.datetime(1, 0, 255, 0, 0)

I think this is bug in datetime for all Python versions