diff -up firefox-8.0/mozilla-release/browser/app/profile/firefox.js.old firefox-8.0/mozilla-release/browser/app/profile/firefox.js
--- firefox-8.0/mozilla-release/browser/app/profile/firefox.js.old	2011-11-04 22:33:52.000000000 +0100
+++ firefox-8.0/mozilla-release/browser/app/profile/firefox.js	2011-11-14 23:21:49.841058452 +0100
@@ -77,7 +77,7 @@ pref("extensions.update.autoUpdateDefaul
 // Disable add-ons installed into the shared user and shared system areas by
 // default. This does not include the application directory. See the SCOPE
 // constants in AddonManager.jsm for values to use here
-pref("extensions.autoDisableScopes", 15);
+pref("extensions.autoDisableScopes", 0);
 
 // Dictionary download preference
 pref("browser.dictionaries.download.url", "https://addons.mozilla.org/%LOCALE%/firefox/dictionaries/");