1. Edit your favorite existing view.
2. Look for the bold text that says "SORT CRITERIA".
3. Look for the Add button and the arrow button.
4. Click the arrow button and choose "Rearrange".
5. In the popup window, click "Remove" on any sort criteria.
6. See page not found error.
I'm using Drupal 7.23, ctools 7.x-1.3, and panels 7.x-3.3 .
I'm also seen other quirks with this version of views.
I'm getting desperate and I might try using the "7.x-3.x-dev" version of views.