diff --git a/libraries/Menu.class.php b/libraries/Menu.class.php
index dcc7f2b73c..88719d116d 100644
--- a/libraries/Menu.class.php
+++ b/libraries/Menu.class.php
@@ -425,7 +425,7 @@ class PMA_Menu
     {
         $is_superuser = PMA_isSuperuser();
         $binary_logs = null;
-        if (! PMA_DRIZZLE) {
+        if (!defined('PMA_DRIZZLE') || (defined('PMA_DRIZZLE') && ! PMA_DRIZZLE)) {
             $binary_logs = PMA_DBI_fetch_result(
                 'SHOW MASTER LOGS',
                 'Log_name',
@@ -495,7 +495,7 @@ class PMA_Menu
         $tabs['charset']['link'] = 'server_collations.php';
         $tabs['charset']['text'] = __('Charsets');
 
-        if (PMA_DRIZZLE) {
+        if (defined('PMA_DRIZZLE') && PMA_DRIZZLE) {
             $tabs['plugins']['icon'] = 'b_engine.png';
             $tabs['plugins']['link'] = 'server_plugins.php';
             $tabs['plugins']['text'] = __('Plugins');
diff --git a/libraries/plugins/PluginObserver.class.php b/libraries/plugins/PluginObserver.class.php
index 190f02d747..6e56e8d201 100644
--- a/libraries/plugins/PluginObserver.class.php
+++ b/libraries/plugins/PluginObserver.class.php
@@ -43,12 +43,19 @@ abstract class PluginObserver implements SplObserver
      * This method is called when any PluginManager to which the observer
      * is attached calls PluginManager::notify()
      *
+     * TODO Declare this function abstract, removing its body, 
+     * as soon as we drop support for PHP 5.2.x.
+     * See bug #3538655.
+     *
      * @param SplSubject $subject The PluginManager notifying the observer
      *                            of an update.
      *
      * @return void
      */
-    abstract public function update (SplSubject $subject);
+    public function update (SplSubject $subject)
+    {
+        throw new Exception('PluginObserver::update must be overridden in child classes.');
+    }
 
     
     /* ~~~~~~~~~~~~~~~~~~~~ Getters and Setters ~~~~~~~~~~~~~~~~~~~~ */
@@ -78,4 +85,4 @@ abstract class PluginObserver implements SplObserver
         $this->_pluginManager = $_pluginManager;
     }
 }
-?>
\ No newline at end of file
+?>