Strange behaviour of the notebooks - main window and side bar (doubled notebooks, notebook menu is not opening) ver. 10.7.6 (2321)

[leog77 0]

Hello, i have the following trouble with the notebooks in the latest version of the MAC APP:

- one new notebook i have created has doubled and clicking on one of them opens both, plus the top one notebook out of two has one note shown on a separate line.

- also the notebook menu item on the sidebar do not collapse when clicking on the triangle near the menu item - no hierarchy shown.