Happens with Python 2.5.2 on 64bit also:

Python 2.5.2 (r252:60911, Apr 21 2008, 11:17:30) 
[GCC 4.2.3 (Ubuntu 4.2.3-2ubuntu7)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import platform
>>> platform.architecture()
('64bit', '')
>>> from cPickle import Pickler
>>> class rec:
...   child = None
...   def __init__(self, counter):
...     if counter > 0:
...       self.child = rec(counter-1)
... 
>>> import sys
>>> sys.setrecursionlimit(10000)
>>> mychain = rec(2600)
>>> from cStringIO import StringIO
>>> stream = StringIO()
>>> p = Pickler(stream, 1)
>>> res = p.dump(mychain)
Segmentation fault