--- form.py.orig	2010-02-26 20:57:28.128506527 +0900
+++ form.py	2010-02-26 23:02:25.668507630 +0900
@@ -572,6 +572,8 @@
             if _identifier.match(label):
                 name = unicode(label).lower()
             else:
+                if isinstance(label, unicode):
+                    label = label.encode('utf-8')
                 name = label.encode('hex')
 
         self.name = name