I've met my share of error dialogs through the years. Ones that say "Something bad has happened. Ok?" are annoying but understandable.
However, one in gpk-update-viewer, which I encountered yesterday, is a real head-scratcher:
This dialog sometimes appears when you try to close the gpk-update-viewer window while updating and it reads:
Cannot cancel running task
There are tasks that cannot be cancelled.
Quite apart from the fact that this dialog shouldn't appear at all -- packagekit will continue the update in the background -- the two buttons appear to mean the same thing, both of which are (according to the dialog) impossible.
These are my first two books: X Power Tools, a thorough guide to the X Window System (O'Reilly, ISBN 9780596101954) and Fedora Linux: A Complete Guide to Red Hat's Community Distro, a practical hands-on book on Fedora (O'Reilly, ISBN 9780596526825).
Fedora Linux is also available for online reading through Safari and in downloadable PDF format from oreilly.com