diff --git a/reviewboard/accounts/backends.py b/reviewboard/accounts/backends.py
--- a/reviewboard/accounts/backends.py
+++ b/reviewboard/accounts/backends.py
@@ -231,7 +231,11 @@ class ActiveDirectoryBackend(object):
                 for group in new_groups:
                     if group in old_seen:
                         continue
-                    group_data = self.search_ad(con, '(&(objectClass=group)(saMAccountName=%s))' % group)
+
+                    # Search for groups with the specified CN. Use the CN rather than
+                    # The sAMAccountName so that behavior is correct when the values
+                    # differ (e.g. if a "pre-Windows 2000" group name is set in AD)
+                    group_data = self.search_ad(con, '(&(objectClass=group)(cn=%s))' % group)
                     seen.update(self.get_member_of(con, group_data, seen=seen, depth=depth))
             else:
                 logging.warning('ActiveDirectory recursive group check reached maximum recursion depth.')