sudo apt-get install nautilus-dropbox && sudo add-apt-repository ppa:xubuntu-dev/extras && sudo apt-get update && sudo apt-get install thunar-dropbox-plugin

Fehlerhaftes Icon im Tray:

dropbox stop && DBUS_SESSION_BUS_ADDRESS=„“ dropbox start

http://askubuntu.com/questions/732967/dropbox-icon-is-not-working-xubuntu-14-04-lts-64