Indeed there seems to be regressions:

Python 2.4 :

[~]> python
Python 2.4.4 (#1, Oct 23 2007, 11:25:50)
[GCC 3.4.6] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import locale
>>> locale.setlocale(locale.LC_ALL,"")
'tr_TR.UTF-8'
>>> print unicode("ıııı")
ıııı
>>> print unicode("ıııı").upper()
IIII
>>> print unicode("iiiii").upper()
İİİİİ
>>> print unicode("İİİİİ").lower()
iiiii
>>> print unicode("IIIIIII").lower()
ııııııı


Python 2.5 (incorrect) :

>>> import locale
>>> locale.setlocale(locale.LC_ALL,"")
'tr_TR.UTF-8'
>>> print unicode("iiiii").upper()
IIIII
>>> print unicode("ıııı").upper()
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
UnicodeDecodeError: 'ascii' codec can't decode byte 0xc4 in position 0:
ordinal not in range(128)
>>> print unicode("iiii").upper()
IIII


Looks like wctypes should not be dropped.