Description of problem:

When I have installed yum-plugin-remove-with-leaves plugin for yum, and tried to install (not remove) a pakcage, I got this backtrace:

Traceback (most recent call last):
  File "/usr/share/PackageKit/helpers/yum/yumBackend.py", line 1215, in _get_depends_not_installed
    rc, msgs =  self.yumbase.buildTransaction()
  File "/usr/lib/python2.6/site-packages/yum/__init__.py", line 719, in buildTransaction
    self.plugins.run('postresolve', rescode=rescode, restring=restring)
  File "/usr/lib/python2.6/site-packages/yum/plugins.py", line 179, in run
    func(conduitcls(self, self.base, conf, **kwargs))
  File "/usr/lib/yum-plugins/remove-with-leaves.py", line 71, in postresolve_hook
    if opts.remove_leaves or remove_always:
AttributeError: 'NoneType' object has no attribute 'remove_leaves'


Version-Release number of selected component (if applicable):
yum-plugin-remove-with-leaves.noarch 0:1.1.21-2.fc11 
gnome-packagekit-2.27.2-0.2.20090414git.fc11.x86_64

How reproducible:
happened once

Steps to Reproduce:
1.see above
2.
3.