This is related to #504 but not caused by it I think.

1. Create a conference.
2. Enter the conference setting screen.
3. Modify the conference acronym to be invalid by adding an uppercase letter, or a space.
4. Click "Update Conference"
5. You get "Acronym is invalid". so far so good.
6. Click Days or Tracks or Rooms or Schedule or Classifiers or Notifications from the tabs bar.
7. You get "The page you were looking for doesn't exist." :-(

The URL being navigated to includes the new, invalid acronym, and not the valid, unchanged one.