1. At <http://launchpad.dev/ubuntu/+filebug-advanced> (or the second stage of <http://launchpad.dev/ubuntu/+filebug?no-redirect>), enter "gnome-default-applications-properties" in the package field.
2. Enter dummy text in the "Summary:" and "Further information:" fields, and click "Submit Bug Report".
3. Observe the resulting error: "'gnome-default-applications-properties' does not exist in Ubuntu. Please choose a different package. If you're unsure, please select 'I don't know'"
4. Select "I don't know", and click "Submit Bug Report" once more.
What should happen:
* The bug report is posted.
What actually happens:
* You're returned to the bug-reporting page with the message "There is 1 error".
* There is no indication of what that error is (bug 66552).
* "I don't know" is no longer selected. If you select it and click "Submit Bug Report", the problem repeats.
I just ran into this too.