Description of problem:
preupgrade can't start because it can't open the display

Version-Release number of selected component (if applicable):
preupgrade-1.1.10-1.fc16.noarch

How reproducible:
Always

Steps to Reproduce:
1. Start a KDE session
2. Run konsole
3. In konsole, run preupgrade
  
Actual results:
Authentication dialog appears asking for my root password.

Then, in konsole

No protocol specified
Traceback (most recent call last):
  File "/usr/share/preupgrade/preupgrade-gtk.py", line 53, in <module>
    import gtk
  File "/usr/lib64/python2.7/site-packages/gtk-2.0/gtk/__init__.py", line 64, in <module>
    _init()
  File "/usr/lib64/python2.7/site-packages/gtk-2.0/gtk/__init__.py", line 52, in _init
    _gtk.init_check()
RuntimeError: could not open display

Expected results:


Additional info:
xterm can start from the same konsole, so there isn't a problem with the DISPLAY variable, which is set to:
:0