don't crash when encountering bad marshal data
diff --git a/Mac/Tools/IDE/MacPrefs.py b/Mac/Tools/IDE/MacPrefs.py
index f8888fc..b1fa7ca 100644
--- a/Mac/Tools/IDE/MacPrefs.py
+++ b/Mac/Tools/IDE/MacPrefs.py
@@ -50,7 +50,8 @@
 		self._prefsdict = {}
 		try:
 			prefdict = marshal.load(open(self.__path, 'rb'))
-		except IOError:
+		except (IOError, ValueError):
+			# file not found, or currupt marshal data
 			pass
 		else:
 			for key, value in prefdict.items():