The system (NTFS + WinXP) doesn't appear to work that way.

As you can see, the system says the parent directory (".") was last modified earlier than when the child directory ("dir2") was last modified:

>dir dir1
 Volume in drive C is C
 Volume Serial Number is 28AB-0E8B

 Directory of C:\Documents and Settings\ikegami\dir1

2009/08/28  12:43 PM    <DIR>          .
2009/08/28  12:43 PM    <DIR>          ..
2009/08/28  12:44 PM    <DIR>          dir2
[download]

Perl reports the same.