warning when upgrading xlibs (sid)

[Pollywog <croak@shadypond.com>]

I ran 'apt-get upgrade' and got this when the xlibs package was upgraded.  I hope I have not just broken X.
Unfortunately, this warning does not really tell me what I need to do:

Preparing to replace xlibs 4.0.2-1 (using .../xlibs_4.0.2-7_i386.deb) ...
Warning: /usr/X11R6/lib/X11/app-defaults is a directory that should be a
symbolic link.
                                  
      A symbolic link to what??



  Packages containing files in /usr/X11R6/lib/X11/app-defaults
need to move them to /etc/X11/app-defaults instead; they will not be used
by the X Window System until they are moved.

     Does this mean I should not upgrade any X stuff?


thanks

--
Andrew