Index: optparse.py
===================================================================
--- optparse.py	(revision 63501)
+++ optparse.py	(working copy)
@@ -1383,7 +1383,7 @@
         try:
             stop = self._process_args(largs, rargs, values)
         except (BadOptionError, OptionValueError), err:
-            self.error(str(err))
+            self.error(err)
 
         args = largs + rargs
         return self.check_values(values, args)
@@ -1554,7 +1554,7 @@
 
     def exit(self, status=0, msg=None):
         if msg:
-            sys.stderr.write(msg)
+            print >>sys.stderr, msg
         sys.exit(status)
 
     def error(self, msg):
@@ -1565,7 +1565,7 @@
         should either exit or raise an exception.
         """
         self.print_usage(sys.stderr)
-        self.exit(2, "%s: error: %s\n" % (self.get_prog_name(), msg))
+        self.exit(2, _("%s: error: %s\n") % (self.get_prog_name(), msg))
 
     def get_usage(self):
         if self.usage:
@@ -1639,7 +1639,8 @@
     def _get_encoding(self, file):
         encoding = getattr(file, "encoding", None)
         if not encoding:
-            encoding = sys.getdefaultencoding()
+            import locale
+            encoding = locale.getpreferredencoding()
         return encoding
 
     def print_help(self, file=None):