Comment 1 for bug 665450

Make sure the following dependencies got installed:

python
python-xdg
python-cairo
python-gtk2 - that includes pygtk and python-pango
python-gnomeapplet *** necessary only when running on gnome-panel *** - or in some distros "python gnome desktop"
python-xml - may be needed in older distributions (eg: ubuntu before karmic)

The following recommended packages should be installed to have fullfuctionality.

gmenu - will use this instead of xdg if it is installed
python-numpy - for gtk theme colors and some tab effects
python-gconf - or in some distros "python gnome"
python-keybinder or python-xlib - for keybinding
gettext - for translations