With version 1.1.5-1, I performed the following steps without exiting the program:

1) Selected to remove gqview -- it uninstalled successfully
2) Selected to installe gqview -- it installed successfully
3) Selected to uninstall the Engineering and Scientific package group --
it stopped at the Preparing system update dialog with the Continue button
still grayed out and gave me:

* Core references package efibootmgr which doesn't exist
* Core references package elilo which doesn't exist
* depcheck: package pvm-gui needs pvm (not provided)
* depcheck: package amanda-server needs gnuplot (not provided)
Traceback (most recent call last):
  File "/usr/share/redhat-config-packages/MainWindow.py", line 63, in response_cb
    self.im.setupTransaction(comps, progress_dialog)
  File "/usr/share/redhat-config-packages/method.py", line 181, in setupTransaction
    raise UnresolvableDependencies (unresolvable_dependencies)
  File "/usr/share/redhat-config-packages/method.py", line 55, in __init__
    exceptions.Exception.__init__()
TypeError: unbound method __init__() must be called with Exception instance as
first argument (got nothing instead)