can't launch Gnome on bootup

[Karl Brandt]

I've been unable to get Gnome to start up on boot. I've used cvsup,
pkgdb -fu, and portupgrade -a multiple times to get all my ports to
build properly. I've added gnome_enable="YES" to /etc/rc.conf. I
believe I've done all the changes in /usr/ports/UPDATING, but I could
have missed something.

banner ~>uname -a
FreeBSD banner 6.2-RELEASE FreeBSD 6.2-RELEASE #0: Fri Jan 12 10:40:27
UTC 2007
root at dessler.cse.buffalo.edu:/usr/obj/usr/src/sys/GENERIC  i386

Here are the relevant lines from /var/log/messages:

Nov 21 15:20:55 banner kernel: Trying to mount root from ufs:/dev/ad0s1a
Nov 21 15:21:10 banner avahi-daemon[841]: WARNING: No NSS support for
mDNS detected, consider installing nss-mdns!
Nov 21 15:21:12 banner gdm-binary[838]: WARNING:
gdm_slave_xioerror_handler: Fatal X error - Restarting :0
Nov 21 15:21:12 banner sm-mta[864]: My unqualified host name (banner)
unknown; sleeping for retry
Nov 21 15:21:15 banner gdm-binary[865]: WARNING:
gdm_slave_xioerror_handler: Fatal X error - Restarting :0
Nov 21 15:21:18 banner gdm-binary[867]: WARNING:
gdm_slave_xioerror_handler: Fatal X error - Restarting :0
Nov 21 15:21:18 banner gdm-binary[832]: WARNING: Failed to start X
server several times in a short time period; disabling display :0
Nov 21 15:22:12 banner sm-mta[864]: unable to qualify my own domain
name (banner) -- using short name
Nov 21 15:22:12 banner sm-msp-queue[888]: My unqualified host name
(banner) unknown; sleeping for retry
Nov 21 15:23:12 banner sm-msp-queue[888]: unable to qualify my own
domain name (banner) -- using short name
Nov 21 15:23:12 banner inetd[919]: ssh/tcp: bind: Address already in use

If it matters, this is on a Dell GX260.

At this point, I'm stumped and don't know what to try next.

-Karl