Has anyone seen the following error when running xvnc11:

XOpenDisplay failed (:0)

I compliled both xvnc11 and libvncserver. Both seemed to compile fine. I am runing this on Fedora Core 1 that has alll packages installed (everything option in anaconda). I know I have all the required libraries and stuff. Here is the complete output from x11vnc:

[mediaboy@brain mediaboy]$ x11vnc -display :0 -rfbauth .vnc/passwd
passing arg to libvncserver: -rfbauth
passing arg to libvncserver: .vnc/passwd

display: :0
subwin: 0x0
visual: null
flashcmap: 0
force_idx: 0
viewonly: 0
shared: 0
authfile: null
passfile: null
logfile: null
allow: null
accept: null
gone: null
conn_once: 1
connect: null
connectfile null
vnc_conn: 0
inetd: 0
using_shm: 1
flipbytes: 0
mod_tweak: 0
remap: null
blackout: null
xinerama: 0
watchbell: 1
nofb: 0
watchsel: 1
watchprim: 1
loc_curs: 1
mouse: 0
root_curs: 0
xwarpptr: 0
cursorpos: 0
buttonmap: null
dragging: 1
inputskip: 10
old_ptr: 0
onetile: 0
debug_ptr: 0
debug_key: 0
defer: 30
waitms: 30
take_naps: 0
sigpipe: 1
threads: 0
fs_frac: 0.75
gaps_fill: 4
grow_fill: 3
tile_fuzz: 2
use_hints: 1
bg: 0
lastmod: 2004-05-27
XOpenDisplay failed (:0)

You do have a current X-Session running when you are doing this right? That error basically means it doesn't detect an active X-Session on display :0