Mouse click on a DVD menu item navigates to too deep level

[Toshio Ito]

- Xubuntu 14.04 (fresh installed)
- totem: 3.10.1-1ubuntu4

Problem:

When I mouse-click on a DVD menu item, it navigates to one extra level
deeper than it should.

For example, suppose the DVD menu is arranged like that:

- [Play All]
- [Episodes]

  - [Episode 1]

    - [Without Commentary]
    - [With Commentary]

  - [Episode 2]
  - [Episode 3]
  - ...

- [Setup]

When I hit [Episodes] item at the top level, it skips the list of
episodes, showing the menu for episode 1 (with or without commentary).
It should navigate to the list of episodes.

With keyboard (arrow keys and Enter key), it navigates correctly.