=== modified file 'includes/module.inc'
--- includes/module.inc	
+++ includes/module.inc	
@@ -141,8 +141,8 @@ function module_implements($hook) {
       }
     }
   }
-
-  return $implementations[$hook];
+  // (array) creates a copy and works around a PHP bug
+  return (array)$implementations[$hook];
 }
 
 /**