In my checkout of py3k (r83123), test_getgroups in test_posix fails - the right elements are returned but the ordering is different:

$ ./python -m test.regrtest test_posix
test_posix
test test_posix failed -- Traceback (most recent call last):
  File "/home/daz/src/py3k/Lib/test/test_posix.py", line 360, in test_getgroups
    self.assertEqual([int(x) for x in groups.split()], posix.getgroups())
AssertionError: Lists differ: [1000, 4, 6, 20, 24, 46, 105, ... != [4, 6, 20, 24, 46, 105, 119, 1...

First differing element 0:
1000
4

- [1000, 4, 6, 20, 24, 46, 105, 119, 122, 125, 126, 128]
+ [4, 6, 20, 24, 46, 105, 119, 122, 125, 126, 128, 1000]

1 test failed:
    test_posix

Platform is Ubuntu 10.04 x86_64, kernel is 2.6.32 - unfortunately my C sucks so I'm not sure what's going on.