diff -Nrbu seamonkey-2.26/comm-release/mail/app/profile/all-thunderbird.js seamonkey-2.26-OK/comm-release/mail/app/profile/all-thunderbird.js

--- seamonkey-2.26/comm-release/mail/app/profile/all-thunderbird.js	2014-04-29 08:55:07.000000000 +0400

+++ seamonkey-2.26-OK/comm-release/mail/app/profile/all-thunderbird.js	2014-05-06 21:38:43.918496556 +0400

@@ -174,7 +174,7 @@

 // 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);

 // Preferences for AMO integration

 pref("extensions.getAddons.cache.enabled", true);

diff -Nrbu seamonkey-2.26/comm-release/mozilla/toolkit/mozapps/extensions/internal/XPIProvider.jsm seamonkey-2.26-OK/comm-release/mozilla/toolkit/mozapps/extensions/internal/XPIProvider.jsm

--- seamonkey-2.26/comm-release/mozilla/toolkit/mozapps/extensions/internal/XPIProvider.jsm	2014-04-29 09:03:18.000000000 +0400

+++ seamonkey-2.26-OK/comm-release/mozilla/toolkit/mozapps/extensions/internal/XPIProvider.jsm	2014-05-06 21:38:43.920496556 +0400

@@ -2051,8 +2051,8 @@

         this.showUpgradeUI();

         flushCaches = true;

       }

-      else if (aAppChanged === undefined) {

-        // For new profiles we will never need to show the add-on selection UI

+    else {

+      // For all profiles we will never need to show the add-on selection UI

         Services.prefs.setBoolPref(PREF_SHOWN_SELECTION_UI, true);

       }