Index: branches/RC/core/install/install_toolkit.php
===================================================================
diff -u -N -r10832 -r10886
--- branches/RC/core/install/install_toolkit.php	(.../install_toolkit.php)	(revision 10832)
+++ branches/RC/core/install/install_toolkit.php	(.../install_toolkit.php)	(revision 10886)
@@ -108,7 +108,7 @@
 
 			$prerequisite_object = new $prerequisite_class();
 			if (method_exists($prerequisite_object, 'setToolkit')) {
-				$prerequisite_object->setToolkit(&$this);
+				$prerequisite_object->setToolkit($this);
 			}
 
 			// some errors possible
Index: branches/RC/core/install.php
===================================================================
diff -u -N -r10832 -r10886
--- branches/RC/core/install.php	(.../install.php)	(revision 10832)
+++ branches/RC/core/install.php	(.../install.php)	(revision 10886)
@@ -834,7 +834,7 @@
 
 			$upgrade_object = new $upgrade_classes[$module_path]();
 			if (method_exists($upgrade_object, 'setToolkit')) {
-				$upgrade_object->setToolkit(&$this->toolkit);
+				$upgrade_object->setToolkit($this->toolkit);
 			}
 
 			foreach ($versions as $version) {