xauth warning

[Phil Dybvig]

Hi!  When I use ssh between some machines (including two machines I have running 
FC2), I am getting the warning

  Warning: No xauth data; using fake authentication data for X11 forwarding.

This sounds like a possible security problem.  Does anyone know what this means?
I am using window maker, so it is possible this is something that would be cared
for automatically by gnome.