Steps to reproduce:
- Hover over Home and click on "Administer Wiki"
- Click on "Panel Wizard"
- Drag and drop some Statistics panels from the panel list to the sides; for ex. you can use Current Month Activity, Most Viewed Pages, Most Referred Pages, Current Year Activity etc.
- Click "Save The New Layout"
- Reload the page
- Try to drag and drop the previously added panels from the sides to the panel list; you'll notice you're unable to remove them (before.png)
- Click "Save The New Layout" even if there's no visible change
- Reload the page (after.png); as you can see from the image the other 2 panels have been removed.
If you try to remove the Statistics panels again (steps 6 & 7) they'll be removed.
Reproduces on both Firefox & Chrome.