I was also getting this same error. DBX was also not launching when added as an applet to AWN (0.40).
For what it is worth installing the following packages (running Linux Mint 9 x64) solved this for me:
sudo add-apt-repository ppa:zeitgeist/ppa && sudo apt-get update sudo apt-get install libgtk2.0-0 libx11-6 libxcomposite1 zeitgeist
I was also getting this same error. DBX was also not launching when added as an applet to AWN (0.40).
For what it is worth installing the following packages (running Linux Mint 9 x64) solved this for me:
sudo add-apt-repository ppa:zeitgeist/ppa && sudo apt-get update
sudo apt-get install libgtk2.0-0 libx11-6 libxcomposite1 zeitgeist