diff --git a/hyde/generator.py b/hyde/generator.py
index 09fc4ef..40ea573 100644
--- a/hyde/generator.py
+++ b/hyde/generator.py
@@ -111,6 +111,12 @@ class Generator(object):
         self.events.generation_complete()
 
     def has_resource_changed(self, resource):
+        """
+        Checks if the given resource has changed since the
+        last generation.
+        """
+        self.load_site_if_needed()
+        self.load_template_if_needed()
         target = File(self.site.config.deploy_root_path.child(
                                 resource.relative_deploy_path))
         if not target.exists or target.older_than(resource.source_file):
diff --git a/hyde/server.py b/hyde/server.py
index 396905a..a5d566e 100644
--- a/hyde/server.py
+++ b/hyde/server.py
@@ -46,7 +46,13 @@ class HydeRequestHandler(SimpleHTTPRequestHandler):
                 site = self.server.site
                 res = site.content.resource_from_relative_path(
                         site.config.not_found)
-                self.redirect("/" + res.relative_deploy_path)
+                if not res:
+                    logger.error(
+                        "Cannot find the 404 template[%s]."
+                            % site.config.not_found)
+                    return "Requested resource not found"
+                else:
+                    self.redirect("/" + res.relative_deploy_path)
 
     def translate_path(self, path):
         """