FreeBSD reinstall still proving awkward

Yesterday, I explained that, having failed to recover from the dreaded FreeBSD "portupgrade -a" turmoil, I had given up the ghost and reinstalled FreeBSD 8.2-RELEASE from CD and was about the start the port install of Gnome.
However, even after a clean install, I couldn't get this to work.
First of all, the "make install clean" of /usr/ports/x11/gnome2 errored out when trying to install /multimedia/totem.
However, immediately after the error out, I cd'ed to /usr/ports/multimedia/totem and issued the "make install clean" command and it installed without problem.
After restarting the /x11/gnome2 install, I let it run overnight. However, once again it errored out, this time while trying to install /sysutils/lsof because of "can't read /usr/src/sys/kern/kern_lockf.c" which apparently means the source code is not available on the HDD.
I didn't even bother to figure this out and just went ahead and reinstalled FreeBSD once again (yet another clean install) but I noted in this video about Gnome2 installation in FreeBSD that /x11/xorg should be installed FIRST.
And this I had not done.
However, this time I did install /x11/xorg first.
So, my sequence of activities after the install (without installing ports from CD) is:
1. portsnap fetch extract
2. portsnap fetch update
3. install xorg from /usr/ports/x11/xorg
4. install Gnome2 from /usr/ports/x11/gnome2

Because these are very long-drawn-out installs, it's advisable to do a
# make config-recursive
before starting in order to avoid the compilation stopping frequently to allow you to choose otpions.

xorg installed cleanly withoiut errors in about 1 hour.
I'm still installing Gnome2 so can't say anything yet.........................to be continued