Original followup by esrever_otua:

"""
Running copy.deepcopy against such an object fails as well for the same reason (Maximum recursion depth exceeded).
	>>> y = deepcopy(x)
	2007-09-25 12:25:10 ERROR ZODB.Connection Couldn't load state for 0x209fe1
	Traceback (most recent call last):
	  File "/u01/app/zope-2.8.7/lib/python/ZODB/Connection.py", line 704, in setstate
	    self._setstate(obj)
	  File "/u01/app/zope-2.8.7/lib/python/ZODB/Connection.py", line 758, in _setstate
	    self._reader.setGhostState(obj, p)
	  File "/u01/app/zope-2.8.7/lib/python/ZODB/serialize.py", line 495, in setGhostState
	    state = self.getState(pickle)
	  File "/u01/app/zope-2.8.7/lib/python/ZODB/serialize.py", line 488, in getState
	    return unpickler.load()
	  File "/u01/app/zope-2.8.7/lib/python/ZODB/serialize.py", line 436, in _persistent_load
	    return self._conn.get(oid)
	  File "/u01/app/zope-2.8.7/lib/python/ZODB/Connection.py", line 207, in get
	    p, serial = self._storage.load(oid, self._version)
	  File "/u01/app/zope-2.8.7/lib/python/ZEO/ClientStorage.py", line 746, in load
	    return self.loadEx(oid, version)[:2]
	  File "/u01/app/zope-2.8.7/lib/python/ZEO/ClientStorage.py", line 769, in loadEx
	    data, tid, ver = self._server.loadEx(oid, version)
	  File "/u01/app/zope-2.8.7/lib/python/ZEO/ServerStub.py", line 192, in loadEx
	    return self.rpc.call("loadEx", oid, version)
	  File "/u01/app/zope-2.8.7/lib/python/ZEO/zrpc/connection.py", line 531, in call
	    r_flags, r_args = self.wait(msgid)
	  File "/u01/app/zope-2.8.7/lib/python/ZEO/zrpc/connection.py", line 638, in wait
	    asyncore.poll(delay, self._singleton)
	  File "/u01/app/python/lib/python2.3/asyncore.py", line 119, in poll
	    read(obj)
	  File "/u01/app/python/lib/python2.3/asyncore.py", line 73, in read
	    obj.handle_error()
	  File "/u01/app/zope-2.8.7/lib/python/ZEO/zrpc/connection.py", line 453, in handle_error
	    level=logging.ERROR, exc_info=True)
	  File "/u01/app/zope-2.8.7/lib/python/ZEO/zrpc/connection.py", line 327, in log
	    self.logger.log(level, self.log_label + message, exc_info=exc_info)
	  File "/u01/app/python/lib/python2.3/logging/__init__.py", line 959, in log
	    apply(self._log, (level, msg, args), kwargs)
	  File "/u01/app/python/lib/python2.3/logging/__init__.py", line 994, in _log
	    self.handle(record)
	  File "/u01/app/python/lib/python2.3/logging/__init__.py", line 1004, in handle
	    self.callHandlers(record)
	  File "/u01/app/python/lib/python2.3/logging/__init__.py", line 1037, in callHandlers
	    hdlr.handle(record)
	  File "/u01/app/python/lib/python2.3/logging/__init__.py", line 588, in handle
	    rv = self.filter(record)
	RuntimeError: maximum recursion depth exceeded
	Traceback (most recent call last):
	  File "<stdin>", line 1, in ?
	  File "/u01/app/python/lib/python2.3/copy.py", line 222, in deepcopy
	    y = _reconstruct(x, rv, 1, memo)
	  File "/u01/app/python/lib/python2.3/copy.py", line 369, in _reconstruct
	    state = deepcopy(state, memo)
	  File "/u01/app/python/lib/python2.3/copy.py", line 192, in deepcopy

	[ ... Snipped many, many duplicate lines of recursive traceback ...]

	    y = copier(x, memo)
	  File "/u01/app/python/lib/python2.3/copy.py", line 286, in _deepcopy_dict
	    y[deepcopy(key, memo)] = deepcopy(value, memo)
	  File "/u01/app/python/lib/python2.3/copy.py", line 209, in deepcopy
	    reductor = getattr(x, "__reduce_ex__", None)
	  File "/u01/app/zope-2.8.7/lib/python/ZODB/Connection.py", line 704, in setstate
	    self._setstate(obj)
	  File "/u01/app/zope-2.8.7/lib/python/ZODB/Connection.py", line 758, in _setstate
	    self._reader.setGhostState(obj, p)
	  File "/u01/app/zope-2.8.7/lib/python/ZODB/serialize.py", line 495, in setGhostState
	    state = self.getState(pickle)
	  File "/u01/app/zope-2.8.7/lib/python/ZODB/serialize.py", line 488, in getState
	    return unpickler.load()
	  File "/u01/app/zope-2.8.7/lib/python/ZODB/serialize.py", line 436, in _persistent_load
	    return self._conn.get(oid)
	  File "/u01/app/zope-2.8.7/lib/python/ZODB/Connection.py", line 207, in get
	    p, serial = self._storage.load(oid, self._version)
	  File "/u01/app/zope-2.8.7/lib/python/ZEO/ClientStorage.py", line 746, in load
	    return self.loadEx(oid, version)[:2]
	  File "/u01/app/zope-2.8.7/lib/python/ZEO/ClientStorage.py", line 769, in loadEx
	    data, tid, ver = self._server.loadEx(oid, version)
	  File "/u01/app/zope-2.8.7/lib/python/ZEO/ServerStub.py", line 192, in loadEx
	    return self.rpc.call("loadEx", oid, version)
	  File "/u01/app/zope-2.8.7/lib/python/ZEO/zrpc/connection.py", line 531, in call
	    r_flags, r_args = self.wait(msgid)
	  File "/u01/app/zope-2.8.7/lib/python/ZEO/zrpc/connection.py", line 638, in wait
	    asyncore.poll(delay, self._singleton)
	  File "/u01/app/python/lib/python2.3/asyncore.py", line 119, in poll
	    read(obj)
	  File "/u01/app/python/lib/python2.3/asyncore.py", line 73, in read
	    obj.handle_error()
	  File "/u01/app/zope-2.8.7/lib/python/ZEO/zrpc/connection.py", line 453, in handle_error
	    level=logging.ERROR, exc_info=True)
	  File "/u01/app/zope-2.8.7/lib/python/ZEO/zrpc/connection.py", line 327, in log
	    self.logger.log(level, self.log_label + message, exc_info=exc_info)
	  File "/u01/app/python/lib/python2.3/logging/__init__.py", line 959, in log
	    apply(self._log, (level, msg, args), kwargs)
	  File "/u01/app/python/lib/python2.3/logging/__init__.py", line 994, in _log
	    self.handle(record)
	  File "/u01/app/python/lib/python2.3/logging/__init__.py", line 1004, in handle
	    self.callHandlers(record)
	  File "/u01/app/python/lib/python2.3/logging/__init__.py", line 1037, in callHandlers
	    hdlr.handle(record)
	  File "/u01/app/python/lib/python2.3/logging/__init__.py", line 588, in handle
	    rv = self.filter(record)
	RuntimeError: maximum recursion depth exceeded
"""