Review of both patches (python-2.5.1-distutils-aixnfs.patch and dir_util.py.diff) as they are essentially the same:

I think that the test is in wrong place: we would want to ignore those .nfs* files always, not just when checking for symlinks. A separate test
at the top of the loop would be better:
    for n in names:
+       if n.startswith('.nfs'):
+           continue
        src_name = os.path.join(src, n)
        dst_name = os.path.join(dst, n)
        if preserve_symlinks and os.path.islink(src_name):


BTW: under linux 2.6.20 I see files like: .nfs000000000592413900000036, always of this length, with hexadecimal digits after .nfs).