extensions page not working properly

Distributor ID: Ubuntu
Description: Ubuntu quantal (development branch)
Release: 12.10
Codename: quantal
gnome-tweak-tool:
  Installed: 3.5.4-0ubuntu1
  Candidate: 3.5.4-0ubuntu1
  Version table:
 *** 3.5.4-0ubuntu1 0
        500 http://us.archive.ubuntu.com/ubuntu/ quantal/universe i386 Packages
        100 /var/lib/dpkg/status

On a completely fresh Quantal install, gnome-tweak-tool fails to show any installed GNOME Shell extensions, despite them being installed. When run from CLI, this output is interesting:
INFO : Missing gsettings org.gnome.nautilus.desktop (key computer-icon-visible)
WARNING : Error listing extensions
Traceback (most recent call last):
  File "/usr/lib/python2.7/dist-packages/gtweak/tweaks/tweak_shell_extensions.py", line 163, in __init__
    for extension in shell.list_extensions().values():
  File "/usr/lib/python2.7/dist-packages/gtweak/gshellwrapper.py", line 130, in list_extensions
    return self._proxy.proxy_extensions.ListExtensions()
AttributeError: _ShellProxy instance has no attribute 'proxy_extensions'
WARNING : Could not list shell extensions
Traceback (most recent call last):
  File "/usr/lib/python2.7/dist-packages/gtweak/tweaks/tweak_shell.py", line 65, in __init__
    extensions = self._shell.list_extensions()
  File "/usr/lib/python2.7/dist-packages/gtweak/gshellwrapper.py", line 130, in list_extensions
    return self._proxy.proxy_extensions.ListExtensions()
AttributeError: _ShellProxy instance has no attribute 'proxy_extensions'

ProblemType: Bug
DistroRelease: Ubuntu 12.10
Package: gnome-tweak-tool 3.5.4-0ubuntu1
ProcVersionSignature: Ubuntu 3.5.0-4.4-generic 3.5.0-rc6
Uname: Linux 3.5.0-4-generic i686
ApportVersion: 2.4-0ubuntu6
Architecture: i386
Date: Sat Aug 11 16:44:43 2012
InstallationMedia: Ubuntu 12.10 "Quantal Quetzal" - Alpha i386 (20120715.1)
PackageArchitecture: all
ProcEnviron:
 TERM=xterm
 PATH=(custom, no user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: gnome-tweak-tool
UpgradeStatus: No upgrade log present (probably fresh install)