Index: usr/share/univention-system-setup/startxwithfirefox
===================================================================
--- usr/share/univention-system-setup/startxwithfirefox	(Revision 34215)
+++ usr/share/univention-system-setup/startxwithfirefox	(Arbeitskopie)
@@ -130,7 +130,8 @@
 # do not show the "know your rights" popup
 echo 'user_pref("browser.rights.3.shown", true);' >> "$profilePath"/prefs.js
 # do not ask for performance reporting
-echo 'user_pref("toolkit.telemetry.prompted", true);' >> "$profilePath"/prefs.js
+echo 'user_pref("toolkit.telemetry.prompted", 2);' >> "$profilePath"/prefs.js
+echo 'user_pref("toolkit.telemetry.rejected", true);' >> "$profilePath"/prefs.js
 # do not store passwords
 echo 'user_pref("signon.rememberSignons", false);' >> "$profilePath"/prefs.js
 # hide tabbar with only one tab