Menu panel is not kept after changing some settings from panel wizard

0. install the menu application: http://extensions.xwiki.org/xwiki/bin/view/Extension/Menu+Application
1. Create a new entry in http://localhost:8080/xwiki/bin/view/Menu/ (setting MENU DISPLAY LOCATION > Inside a left Panel)
2. Go to administration > Page elements and add Menu.MenuTitle into PANELS DISPLAYED ON THE LEFT field.
3. Save the change and check the left app menu.
4. Go again in administration > Panel Wizard > Page Layout
5. Choose this page layout > No side column and Save the change.
6. Change the page layout back to the previous form > Both columns and Save the change.
7. Now, check the left app panel.
8. Go again in the administration > Page elements and check the values from PANELS DISPLAYED ON THE LEFT field.

Actual result:

• After performing step 3 > the menu is displayed as a panel in the left app panel.
• After performing step 7 > the menu was removed from the left app panel
• After performing step 8 > the value "Menu.MenuTitle" set at step 2 wasn`t saved, even if you clicked on Save button.

Expected result:

• The value inserted in PANELS DISPLAYED ON THE LEFT field from Page Elements should be kept, even if you make some changes in the Panel Layout.