After adding a new zone to a layout in zone.ini, the change is not visible when editing an object with that layout attribute.

The only workaround is to choose a different layout (loosing any block costumization), and choose the original layout once more.

Steps to reproduce

• Add a new zone to a layout in used (like the homepage)
• Clear caches, edit the content object with that layout
• The new zone is not displayed, unless a different layout is selected.