Index: src/org/python/parser/TreeBuilder.java
===================================================================
--- src/org/python/parser/TreeBuilder.java	(revision 3250)
+++ src/org/python/parser/TreeBuilder.java	(working copy)
@@ -75,8 +75,14 @@
         new SimpleNode[PythonGrammarTreeConstants.jjtNodeName.length];
 
     public SimpleNode openNode(int id) {
-        if (nodes[id] == null)
+        if (nodes[id] == null) {
+            if (id == JJTNAME || id == JJTSTRING || id == JJTNUM) {
+                // Names, strings and numbers are stored in the image field of
+                // their Node, so don't share these between nodes
+                return new IdentityNode(id);
+            }
             nodes[id] = new IdentityNode(id);
+        }
         return nodes[id];
     }