Method "find_credentials" with signature "s" on interface "(null)" doesn't exist

Run the following program in precise:

===
from ubuntuone.couch import auth
auth.get_oauth_credentials()
===

And you will get the following:

===
Traceback (most recent call last):
  File "u1couch.py", line 3, in <module>
    auth.get_oauth_credentials()
  File "/usr/lib/python2.7/dist-packages/ubuntuone-couch/ubuntuone/couch/auth.py", line 75, in get_oauth_credentials
    proxy.find_credentials(APP_NAME).iteritems())
  File "/usr/lib/python2.7/dist-packages/dbus/proxies.py", line 68, in __call__
    return self._proxy_method(*args, **keywords)
  File "/usr/lib/python2.7/dist-packages/dbus/proxies.py", line 143, in __call__
    **keywords)
  File "/usr/lib/python2.7/dist-packages/dbus/connection.py", line 630, in call_blocking
    message, timeout)
dbus.exceptions.DBusException: org.freedesktop.DBus.Error.UnknownMethod: Method "find_credentials" with signature "s" on interface "(null)" doesn't exist
===

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: ubuntuone-couch 0.3.0-0ubuntu2 [modified: usr/share/pyshared/ubuntuone-couch/ubuntuone/couch/auth.py]
Uname: Linux 3.2.0-030200rc2-generic i686
ApportVersion: 1.90-0ubuntu1
Architecture: i386
CheckboxSubmission: 9a284f3f6b4f7829abbe27ad9573a709
CheckboxSystem: 3935143777c965daaa64b51f0134f712
Date: Tue Dec 27 15:03:17 2011
EcryptfsInUse: Yes
InstallationMedia: Ubuntu 11.04 "Natty Narwhal" - Release i386 (20110422)
PackageArchitecture: all
SourcePackage: ubuntuone-couch
UpgradeStatus: Upgraded to precise on 2011-11-05 (51 days ago)