Can't install Dropbox: Gtk-Message: Failed to load module "canberra-gtk-module"

[Gabriel_P]

After installing Dropbox, the daemon needs to be installed. To do this, Dropbox asks to run the command:

dropbox start -i

which results in:

Starting Dropbox...
(dropbox:8724): Gtk-WARNING **: Imposible encontrar el motor de temas en la ruta al _modulo: «pixmap»,

(dropbox:8724): Gtk-WARNING **: Imposible encontrar el motor de temas en la ruta al _modulo: «pixmap»,

(dropbox:8724): Gtk-WARNING **: Imposible encontrar el motor de temas en la ruta al _modulo: «pixmap»,

(dropbox:8724): Gtk-WARNING **: Imposible encontrar el motor de temas en la ruta al _modulo: «pixmap»,

(dropbox:8724): Gtk-WARNING **: Imposible encontrar el motor de temas en la ruta al _modulo: «pixmap»,
Gtk-Message: Failed to load module "canberra-gtk-module"
Attempt to unlock mutex that was not locked
Abortado (`core' generado)

Using a freshly installed elementary Freya 64 bit system. Things I've installed before Dropbox: Google Chrome, Filezilla, Sublime.

Related: https://bugs.launchpad.net/elementaryos/+bug/1435317

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Installing via this script fixes the issue: https://github.com/nathandyer/elementary-dropbox-mods

[Gabriel_P (gabp)]

Installing:

sudo apt-get install libcanberra-gtk*

makes this issue go away, but then the 'Attempt to unlock mutex that was not locked' issue appears.

Marking this one as a duplicate.