diff -r b758351d191f -r cc9b7e14412b web/lib/django/db/models/expressions.py
--- a/web/lib/django/db/models/expressions.py	Wed May 19 17:43:59 2010 +0200
+++ b/web/lib/django/db/models/expressions.py	Tue May 25 02:43:45 2010 +0200
@@ -1,7 +1,7 @@
-from copy import deepcopy
 from datetime import datetime
 
 from django.utils import tree
+from django.utils.copycompat import deepcopy
 
 class ExpressionNode(tree.Node):
     """
@@ -41,8 +41,8 @@
     def prepare(self, evaluator, query, allow_joins):
         return evaluator.prepare_node(self, query, allow_joins)
 
-    def evaluate(self, evaluator, qn):
-        return evaluator.evaluate_node(self, qn)
+    def evaluate(self, evaluator, qn, connection):
+        return evaluator.evaluate_node(self, qn, connection)
 
     #############
     # OPERATORS #
@@ -109,5 +109,5 @@
     def prepare(self, evaluator, query, allow_joins):
         return evaluator.prepare_leaf(self, query, allow_joins)
 
-    def evaluate(self, evaluator, qn):
-        return evaluator.evaluate_leaf(self, qn)
+    def evaluate(self, evaluator, qn, connection):
+        return evaluator.evaluate_leaf(self, qn, connection)