eggbot_acrostic and eggbot_spiraltext are currently not working, possibly due to a bug in the latest version(s) of Inkscape (e.g., 0.48.5).
A fix has been committed for the upcoming 0.91 release of Inkscape.
Related: https://bugs.launchpad.net/inkscape/+bug/1258473
See also: https://inkscape.org/en/develop/next-release/