Вот что нашел:
Dependencies: This plugin requires either of two libraries: "gtkspell" or "gtkspellcheck", if both are installed, the later is used.
To install "gtkspellcheck":
* On Ubuntu or Debian systems installing the package "python-gtkspellcheck" will meet these dependencies.
To install "gtkspell":
* On Ubuntu or Debian systems installing the package "python-gtkspell" (or "python-gnome2-extras" on older releases) will meet these dependencies.
* On Fedora systems, installing the package "gnome-python2-gtkspell" will meet these dependencies.