Ticket #292 - Allow the results of subclasses of the PythonTranslator to be cached as well.

--HG--
branch : trunk
diff --git a/jinja/loaders.py b/jinja/loaders.py
index e3dccde..4b4937a 100644
--- a/jinja/loaders.py
+++ b/jinja/loaders.py
@@ -239,7 +239,7 @@
         try:
             # caching is only possible for the python translator. skip
             # all other translators
-            if translator is not PythonTranslator:
+            if isinstance(translator, PythonTranslator):
                 return super(CachedLoaderMixin, self).load(
                              environment, name, translator)
 
@@ -363,7 +363,7 @@
         try:
             # caching is only possible for the python translator. skip
             # all other translators
-            if translator is not PythonTranslator:
+            if isinstance(translator, PythonTranslator):
                 return super(MemcachedLoaderMixin, self).load(
                              environment, name, translator)
             tmpl = None