diff --git a/library/Zend/Loader/PluginLoader.php b/library/Zend/Loader/PluginLoader.php
index ca4f1554..b6b1da20 100644
--- a/library/Zend/Loader/PluginLoader.php
+++ b/library/Zend/Loader/PluginLoader.php
@@ -128,7 +128,7 @@ protected function _formatPrefix($prefix)
         }
 
         $last = strlen($prefix) - 1;
-        if ($prefix{$last} == '\\') {
+        if ($prefix[$last] == '\\') {
             return $prefix;
         }
 
diff --git a/library/Zend/Registry.php b/library/Zend/Registry.php
index 4d9036a9..5fe6f88b 100644
--- a/library/Zend/Registry.php
+++ b/library/Zend/Registry.php
@@ -203,7 +203,7 @@ public function __construct($array = array(), $flags = parent::ARRAY_AS_PROPS)
      */
     public function offsetExists($index)
     {
-        return array_key_exists($index, $this);
+        return in_array($index, array_keys($this->getArrayCopy()));
     }
 
 }
diff --git a/library/Zend/Wildfire/Plugin/FirePhp.php b/library/Zend/Wildfire/Plugin/FirePhp.php
index 6ca2f7aa..fcefc3ec 100644
--- a/library/Zend/Wildfire/Plugin/FirePhp.php
+++ b/library/Zend/Wildfire/Plugin/FirePhp.php
@@ -737,7 +737,7 @@ protected function _encodeObject($object, $objectDepth = 1, $arrayDepth = 1)
 
                 $name = $raw_name = $just_name;
 
-                if ($name{0} == "\0") {
+                if ($name[0] == "\0") {
                     $parts = explode("\0", $name);
                     $name = $parts[2];
                 }