In current CVS, test_unicode_file fails on Win98SE.  This 
has been going on for some time, actually.

ERROR: test_single_files (__main__.TestUnicodeFiles)

Traceback (most recent call last):
  File ".../lib/test/test_unicode_file.py", line 162, in 
test_single_files
    self._test_single(TESTFN_UNICODE)
  File ".../lib/test/test_unicode_file.py", line 136, in 
_test_single
    self._do_single(filename)
  File ".../lib/test/test_unicode_file.py", line 49, in 
_do_single
    new_base = unicodedata.normalize("NFD", new_base)
TypeError: normalized() argument 2 must be unicode, 
not str

At this point,

filename is TESTFN_UNICODE is
u'@test-\xe0\xf2'

os.path.abspath(filename) is
'C:\\Code\\python\\PC\\VC6\\@test-\xe0\xf2'

new_base is
'@test-\xe0\xf2

So abspath() removed the "Unicodeness" of filename, 
and new_base is indeed not a Unicode string at this 
point.