'w' Shows 2 users lists one

[John Hubbard]

jhubbard at jhubbard-server:~$ w
 10:54:48 up 32 days,  2:45,  2 users,  load average: 0.32, 0.27, 0.16
USER     TTY      FROM              LOGIN@   IDLE   JCPU   PCPU WHAT
jhubbard :0       -                Mon21   ?xdm?  14:52   0.10s /bin/sh 
/etc/xdg/xfce4/xinitrc -- /etc/X11/xinit/xserverrc

Why does the w command list that I have two users currently logged in 
but only show one.  I realize that there are actually many more than 2 
users logged in (all users with a uid <1000) but either all or none of 
them should be shown.

-- 
-john
There are only 10 kinds of people,
Those who understand binary and those who don't.