Having set up Kubuntu 14.04 at 2014-08-29, doing also:
sudo apt-get update && sudo apt-get dist-upgrade
i do get the interface to pitivi, but no buttons, like + to import clip, no Timeline!
It shows however the text: Import and some icon, looking like a page of paper.

Start with sudo pitivi in teminal:
tuxator@tuxolino:~$ sudo pitivi
[sudo] password for tuxator: 
Missing soft dependency:
- pycanberra not found on the system
    -> aktiviert einen Benachrichtigungston sobald das Erstellen fertig ist
Missing soft dependency:
- GnomeDesktop not found on the system
    -> file thumbnails provided by GNOME's thumbnailers
Missing soft dependency:
- Notify not found on the system
    -> aktiviert visuelle Benachrichtigungen, sobald das Erstellen fertig ist

(pitivi:3822): Gdk-WARNING **: gdk_window_set_icon_list: icons too large
Traceback (most recent call last):
  File "/usr/lib/x86_64-linux-gnu/pitivi/python/pitivi/project.py", line 834, in do_loaded
    self._ensureTracks()
  File "/usr/lib/x86_64-linux-gnu/pitivi/python/pitivi/project.py", line 1022, in _ensureTracks
    for track in self.timeline.get_tracks()]
TypeError: Couldn't find conversion for foreign struct 'cairo.Context'
tuxator@tuxolino:~$ 


starting in terminal as user:

tuxator@tuxolino:~$ pitivi
Missing soft dependency:
- pycanberra not found on the system
    -> aktiviert einen Benachrichtigungston sobald das Erstellen fertig ist
Missing soft dependency:
- GnomeDesktop not found on the system
    -> file thumbnails provided by GNOME's thumbnailers
Missing soft dependency:
- Notify not found on the system
    -> aktiviert visuelle Benachrichtigungen, sobald das Erstellen fertig ist

(pitivi:3927): Gdk-WARNING **: gdk_window_set_icon_list: icons too large
Traceback (most recent call last):
  File "/usr/lib/x86_64-linux-gnu/pitivi/python/pitivi/project.py", line 834, in do_loaded
    self._ensureTracks()
  File "/usr/lib/x86_64-linux-gnu/pitivi/python/pitivi/project.py", line 1022, in _ensureTracks
    for track in self.timeline.get_tracks()]
TypeError: Couldn't find conversion for foreign struct 'cairo.Context'
Traceback (most recent call last):
  File "/usr/lib/x86_64-linux-gnu/pitivi/python/pitivi/project.py", line 1361, in _presetChangedCb
    preset = model[iter_][0]
  File "/usr/lib/python2.7/dist-packages/gi/overrides/Gtk.py", line 1038, in __getitem__
    return self.model.get_value(self.iter, key)
TypeError: Couldn't find conversion for foreign struct 'cairo.Context'

(pitivi:3927): Gdk-CRITICAL **: gdk_device_ungrab: assertion 'GDK_IS_DEVICE (device)' failed

(pitivi:3927): Gtk-CRITICAL **: gtk_device_grab_remove: assertion 'GDK_IS_DEVICE (device)' failed

(pitivi:3927): Gdk-CRITICAL **: gdk_device_ungrab: assertion 'GDK_IS_DEVICE (device)' failed

(pitivi:3927): Gtk-CRITICAL **: gtk_device_grab_remove: assertion 'GDK_IS_DEVICE (device)' failed
tuxator@tuxolino:~$ 

picture can be seen:
[URL=http://www.pic-upload.de/view-24442954/pitivi-0.93-3.png.html][IMG]http://www11.pic-upload.de/thumb/31.08.14/d5pks4dohjap.png[/IMG][/URL]

System-information:
Kubuntu 14.04 LTS
QT-Version: 4.8.6
Kernel-Version: 3.13.0-35-generic
OS: 64-bit
---------
Processor: i7 3770
memory: 16G
Graphic card: nvidia-GTX 580

regards