Resolution too high with 7-RC1, nVidia, xorg

[Xn Nooby]

I am having trouble getting X to use a screen resolution that is less
than the maximum.  When I edit my xorg.conf to add a DefaultDepth and
a Mode of "1024x768", it still comes up at 1280x1024.  I did not
create any modeline entries yet, since I'm not sure how to do that.
My GUI (icewm) works, but browsing the web creates enormous eye-strain
from the high-resolution letters.

My hardware is a Dell Inspiron 530 Desktop with an nVidia Card. It
comes with SATA CD's, so I have to install with FreeBSD 7-RC1.

I started by running "xorg -configure", and used the xorg.conf that it
generated.  I looked at /var/log/Xorg.0.log, and it had many entries
from probing my hardware.  It appears there is some kind of dynamic
configuration going on, but I know its using the xorg.conf, because it
got an error when I changed the adapter entry from "nv" to "vga".

I actually had a similar problem on Ubuntu, and they had some
"xorg-reconfigure" program that would let you use less than maximum
values.  I was wondering if FreeBSD had something similar.

The "DefaultDepth 24" and "Modes "1024x786"" entries are from the
online FreeBSD Handbook, I believe I followed the Handbook
instructions properly.

Am I missing something obvious?  From using Linux, I was expecting the
"Modes" values to work.