Comment 2 for bug 1078627

Sorry for the late response
I had the gnome-icon-theme installed, I added a few more (including gnome-icon-theme-full) and unfortunately I still get the almost the same error. I paste the output below since a few linenumbers are different (the PPA has been updated ?)

$ typecatcher
/usr/lib/python2.7/dist-packages/gi/overrides/Gtk.py:391: Warning: g_object_set_property: construct property "type" for object `Window' can't be set after construction
  Gtk.Window.__init__(self, type=type, **kwds)

(typecatcher:5864): Gtk-WARNING **: Unknown property: GtkEntry.input-hints
Traceback (most recent call last):
  File "/usr/bin/typecatcher", line 47, in <module>
    typecatcher.main()
  File "/usr/lib/python2.7/dist-packages/typecatcher/__init__.py", line 42, in main
    window = TypeCatcherWindow.TypeCatcherWindow()
  File "/usr/lib/python2.7/dist-packages/typecatcher_lib/Window.py", line 48, in __new__
    new_object.finish_initializing(builder)
  File "/usr/lib/python2.7/dist-packages/typecatcher/TypeCatcherWindow.py", line 55, in finish_initializing
    htmlfile = html_font_view()
  File "/usr/lib/python2.7/dist-packages/typecatcher/html_preview.py", line 45, in html_font_view
    installed_icon_uri = installed_info.get_filename()
AttributeError: 'NoneType' object has no attribute 'get_filename'