diff --git a/src/calibre/ptempfile.py b/src/calibre/ptempfile.py
index fe69949f99..f4bcfa8675 100644
--- a/src/calibre/ptempfile.py
+++ b/src/calibre/ptempfile.py
@@ -46,7 +46,10 @@ class PersistentTemporaryFile(object):
         self.close()
 
     def __del__(self):
-        self.close()
+        try:
+            self.close()
+        except:
+            pass
 
 
 def PersistentTemporaryDirectory(suffix='', prefix='', dir=None):
diff --git a/src/calibre/utils/osx_symlinks.py b/src/calibre/utils/osx_symlinks.py
index 2cfdd72fa3..63863cb810 100644
--- a/src/calibre/utils/osx_symlinks.py
+++ b/src/calibre/utils/osx_symlinks.py
@@ -7,6 +7,7 @@ __copyright__ = '2009, Kovid Goyal <kovid@kovidgoyal.net>'
 __docformat__ = 'restructuredtext en'
 
 import sys, os, cPickle
+from calibre.constants import isnewosx
 
 AUTHTOOL="""#!/usr/bin/python
 import os
@@ -27,7 +28,7 @@ for s, l in zip(scripts, links):
 DEST_PATH = '/usr/bin'
 
 def create_symlinks():
-    return create_symlinks_new() if getattr(sys, 'new_app_bundle', False) else create_symlinks_old()
+    return create_symlinks_new() if isnewosx else create_symlinks_old()
 
 def get_scripts():
     return cPickle.load(open(P('scripts.pickle'), 'rb'))