11.10: Using a Python Nautilus extension causes Nautilus to segfault

If I install a nautilus-python based extension for Nautilus in Oneiric and restart Nautilus it segfaults with the following error message

TypeError: metaclass conflict: the metaclass of a derived class must be a (non-strict) subclass of the metaclasses of all its bases
[2] 2991 segmentation fault nautilus

How to reproduce:
Install nautilus-python, create the folder ~/.local/share/nautilus-python/extensions/, copy /usr/share/doc/python-nautilus/examples/open-terminal.py to that folder, run 'nautilus --quit; nautilus'

This bug doesn't exist in 12.04

ProblemType: Bug
DistroRelease: Ubuntu 11.10
Package: python-nautilus 1.0-0ubuntu2
ProcVersionSignature: Ubuntu 3.0.0-15.26-generic 3.0.13
Uname: Linux 3.0.0-15-generic i686
NonfreeKernelModules: nvidia
ApportVersion: 1.23-0ubuntu4
Architecture: i386
Date: Sun Jan 29 15:53:16 2012
InstallationMedia: Ubuntu 11.10 "Oneiric Ocelot" - Release i386 (20111012)
ProcEnviron:
 LC_CTYPE=de_DE.UTF-8
 PATH=(custom, user)
 LANG=de_DE.UTF-8
 SHELL=/bin/zsh
SourcePackage: nautilus-python
UpgradeStatus: No upgrade log present (probably fresh install)