No need to call containsKey on dirtyNodes before putting existing nodes.

src/helma/objectmodel/db/Transactor.java

@@ -131,11 +131,9 @@ public class Transactor {
         if (node != null) {
             Key key = node.getKey();
 
-            if (!dirtyNodes.containsKey(key)) {
             dirtyNodes.put(key, node);
         }
     }
-    }
 
     /**
      * Unmark a Node that has previously been marked as modified during the transaction