[Zope] problem migrating ZClasses from Zope 2.6.1 to Zope 2.9.8

[Yuri]

Hi!

 I've got a trouble importing a ZClass app to 2.9.8 from 2.6.1.

 First, I've tried 2.8, and it worked but had the __new__ problem, so 
I've seen it is fixed in 2.9.8.

 After the upgrade, all seemed to work. My ZClass is a container (with 
ExtFile). I've been able to create a new instance, then had trouble 
after uploading an ExtFile. The file is there, in the repository, but 
when I clicked over it, I get a fast scrolling in the log. After the 
restart, the ZClass instances and the Product in the control panel, 
gived me a maximun recursion depth, here the last part:

  File "/usr/lib/zope2.9.8/lib/python/ZODB/serialize.py", line 597, in 
getState
    return unpickler.load()
  File "/usr/lib/zope2.9.8/lib/python/ZODB/serialize.py", line 471, in 
_persiste
nt_load
    return self.load_oid(reference)
  File "/usr/lib/zope2.9.8/lib/python/ZODB/serialize.py", line 537, in 
load_oid
    return self._conn.get(oid)
  File "/usr/lib/zope2.9.8/lib/python/ZODB/Connection.py", line 205, in get
    obj._p_jar = self
  File "/usr/lib/zope2.9.8/lib/python/ZClasses/_pmc.py", line 65, in 
__setattr__
    super(ZClassPersistentMetaClass, self).__setattr__(name, v)
  File "/usr/lib/zope2.9.8/lib/python/ZODB/persistentclass.py", line 84, 
in __se
t__
    jar.setstate(inst)
  File "/usr/lib/zope2.9.8/lib/python/ZODB/Connection.py", line 732, in 
setstate
    self._setstate(obj)
  File "/usr/lib/zope2.9.8/lib/python/ZODB/Connection.py", line 786, in 
_setstat
e
    self._reader.setGhostState(obj, p)
  File "/usr/lib/zope2.9.8/lib/python/ZODB/serialize.py", line 604, in 
setGhostS
tate
    state = self.getState(pickle)
  File "/usr/lib/zope2.9.8/lib/python/ZODB/serialize.py", line 597, in 
getState
    return unpickler.load()
  File "/usr/lib/zope2.9.8/lib/python/ZODB/serialize.py", line 471, in 
_persiste
nt_load
    return self.load_oid(reference)
  File "/usr/lib/zope2.9.8/lib/python/ZODB/serialize.py", line 537, in 
load_oid
    return self._conn.get(oid)
  File "/usr/lib/zope2.9.8/lib/python/ZODB/Connection.py", line 205, in get
    obj._p_jar = self
  File "/usr/lib/zope2.9.8/lib/python/ZClasses/_pmc.py", line 65, in 
__setattr__
    super(ZClassPersistentMetaClass, self).__setattr__(name, v)
  File "/usr/lib/zope2.9.8/lib/python/ZODB/persistentclass.py", line 84, 
in __se
t__
    jar.setstate(inst)
  File "/usr/lib/zope2.9.8/lib/python/ZODB/Connection.py", line 737, in 
setstate
    exc_info=sys.exc_info())
  File "logging/__init__.py", line 999, in error
  File "logging/__init__.py", line 1078, in _log
  File "logging/__init__.py", line 1064, in makeRecord
  File "logging/__init__.py", line 226, in __init__
    # Must happen after ZopeStarter.setupInitialLogging()
RuntimeError: maximum recursion depth exceeded in cmp
2008-03-26 11:12:05 INFO Signals Caught signal SIGINT
2008-03-26 11:12:07 INFO Z2 Shutting down

=======

 Any idea?