diff -up Python-2.6.6/Python/codecs.c.ascii-tolower Python-2.6.6/Python/codecs.c

--- Python-2.6.6/Python/codecs.c.ascii-tolower	2010-05-09 11:15:40.000000000 -0400

+++ Python-2.6.6/Python/codecs.c	2010-11-29 15:06:20.191352174 -0500

@@ -45,6 +45,11 @@ int PyCodec_Register(PyObject *search_fu

     return -1;

 }

+/* isupper() forced into the ASCII Locale */

+#define ascii_isupper(x) (((x) >= 0x41) && ((x) <= 0x5A))

+/* tolower() forced into the ASCII Locale */

+#define ascii_tolower(x) (ascii_isupper(x) ? ((x) + 0x20) : (x))

+

 /* Convert a string to a normalized Python string: all characters are

    converted to lower case, spaces are replaced with underscores. */

@@ -70,7 +75,7 @@ PyObject *normalizestring(const char *st

         if (ch == ' ')

             ch = '-';

         else

-            ch = tolower(Py_CHARMASK(ch));

+            ch = ascii_tolower(Py_CHARMASK(ch));

         p[i] = ch;

     }

     return v;