Comment 9 for bug 478274

If it can help, here is what /var/log/ConsoleKit/history tells me since I last rebooted:
1258028674.109 type=SEAT_ADDED : seat-id='Seat2' seat-kind=0
1258028721.681 type=SEAT_ADDED : seat-id='Seat3' seat-kind=1
1258028721.931 type=SEAT_SESSION_ADDED : seat-id='Seat3' session-id='Session1' session-type='LoginWindow' session-x11-display=':0' session-x11-display-device='/dev/tty7' session-display-device='' session-remote-host-name='' session-is-local=TRUE session-unix-user=105 session-creation-time='2009-11-12T12:25:21.681323Z'
1258028920.862 type=SEAT_SESSION_REMOVED : seat-id='Seat3' session-id='Session1' session-type='LoginWindow' session-x11-display=':0' session-x11-display-device='/dev/tty7' session-display-device='' session-remote-host-name='' session-is-local=TRUE session-unix-user=105 session-creation-time='2009-11-12T12:25:21.681323Z'
1258028920.862 type=SEAT_REMOVED : seat-id='Seat3' seat-kind=1
1258028920.964 type=SEAT_ADDED : seat-id='Seat4' seat-kind=1
1258028920.986 type=SEAT_SESSION_ADDED : seat-id='Seat4' session-id='Session2' session-type='' session-x11-display=':0' session-x11-display-device='/dev/tty7' session-display-device='' session-remote-host-name='' session-is-local=TRUE session-unix-user=1000 session-creation-time='2009-11-12T12:28:40.964345Z'

Note: output from id gdm = uid=105(gdm) gid=113(gdm) groups=113(gdm)

And ps uaxw | grep gdm:
root 1462 0.0 0.1 74936 3752 ? Ss 13:24 0:00 gdm-binary
root 1508 0.0 0.1 76864 3932 ? S 13:24 0:00 /usr/lib/gdm/gdm-simple-slave --display-id /org/gnome/DisplayManager/Display1
root 1509 2.1 3.9 180276 122132 tty7 Rs+ 13:24 2:05 /usr/bin/X :0 -br -verbose -auth /var/run/gdm/auth-for-gdm-4Q2YHk/database -nolisten tcp vt7
gdm 1925 0.0 0.0 26156 784 ? S 13:25 0:00 /usr/bin/dbus-launch --exit-with-session
root 2513 0.0 0.1 89288 3388 ? S 13:25 0:00 /usr/lib/gdm/gdm-session-worker