The description refers to the "Preferences" button. The button is actually labelled "Configure Plugin". (Seen in 0.2.4.)
This should be an appropriate fix (against trunk).
=== modified file 'GTG/plugins/notification-area.gtg-plugin'
--- GTG/plugins/notification-area.gtg-plugin 2010-03-03 08:20:14 +0000
+++ GTG/plugins/notification-area.gtg-plugin 2010-06-29 14:37:11 +0000
@@ -3,7 +3,7 @@
Name=Notification area
Description="""Adds a GTG icon to the notification area,
that keeps the list of the currently workable tasks.
-To start GTG minimized, click on the 'Preferences' button
+To start GTG minimized, click on the 'Configure Plugin' button
at the bottom of this window."""
Authors="Paulo Cabido <email address hidden>, Luca Invernizzi <email address hidden>, Jono Bacon <email address hidden>"
Version=0.9
