Footer Menu items move to Main Menu after change

Hi folks

Case 1: Postnote quickstart ver. 2.0.1 (J1.5.20) installation on localhost (MAMP 1.9.1) without any changes after install.
--> When trying to rename an item on Footer menu the menu item moves to Main menu on save. On front end it shows under Main Menu.
--> Creating a new menu item and click apply it doesn't move to Main menu but it doesn't show on front end under Footer Menu.

Case 2: Postnote quickstart ver. 2.0 (J1.5.20) installation on localhost (MAMP 1.9.1) without any changes after install.
--> Same as above.

Case 3: Postnote quickstart ver. 1.0.1 (J1.5.19) installation on localhost (MAMP 1.9.1) without any changes after install.
--> Works

Updating to 2.0 and then to 2.0.1
--> Works fine. Updating then to J1.5.20 --> Does not work. Same as case 1.


Case 4: Clean J1.5.20 installation on localhost (MAMP 1.9.1) without any changes after install and then install Postnote template 2.0.1.
--> Works !!! But its worthless as its too much work after to make it look like the demo.


This behavior is with Footer menu only.

As far as I could understand from my tests the problem is with J1.5.20 only. Any ideas?

TIA
Yannis