Could not locate JSEvaluateScript: webkitgtk-3so.so

The gir bindings for JSCore in Webkit-3.0 error when the EvaluateScript object is instantiated.

$ python
Python 2.7.2+ (default, Aug 16 2011, 07:29:45)
[GCC 4.6.1] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> from gi.repository import JSCore
>>> es = JSCore.EvaluateScript()

** (process:16619): WARNING **: Failed to load shared library 'webkitgtk-3.0' referenced by the typelib: webkitgtk-3so.so: cannot open shared object file: No such file or directory
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/lib/python2.7/dist-packages/gi/types.py", line 43, in function
    return info.invoke(*args, **kwargs)
gi._glib.GError: Could not locate JSEvaluateScript: webkitgtk-3so.so: cannot open shared object file: No such file or directory

ProblemType: Bug
DistroRelease: Ubuntu 11.10
Package: gir1.2-webkit-3.0 1.4.3-0ubuntu1
ProcVersionSignature: Ubuntu 3.0.0-10.16-generic-pae 3.0.4
Uname: Linux 3.0.0-10-generic-pae i686
NonfreeKernelModules: nvidia wl
ApportVersion: 1.22.1-0ubuntu2
Architecture: i386
Date: Sat Sep 10 00:14:15 2011
ProcEnviron:
 PATH=(custom, user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: webkit
UpgradeStatus: Upgraded to oneiric on 2011-08-24 (16 days ago)