user directories

Archived from groups: microsoft.public.windowsxp.security_admin (More info?)

I've noticed that my system is duplicating much of my data in the following
two locations:

C:\Documents and Settings\username\
C:\WINDOWS\system32\username\

For example, My Documents, Desktop, Favorites, Userdata...

"My Documents" maps to "C:\Documents and Settings\username\My Documents"
but when I place files there, they eventually show up in
"C:\WINDOWS\system32\username\My Documents" too and I can't figure out when
and why. Of course, this is especially a problem when you are storing big
files in My Documents.

Thanks in advance for any insight.
Mark