I think I figured it out tonight after playing around for an hour or
so. It definitely works now in both OpenGL and Direct3D at all
resolutions

First, what I think the solution is:

A. I think the answer is that you have to Enable the nView Desktop
Manager in the driver. This is the only significant difference that I
found in all my testing.

Second, this is why I think this:

B. In case I am wrong about #1, I will explain what I did, step by step
to cause it to start working.

1. I uninstalled my existing nVidia drivers via Add/Remove Programs.

2. I rebooted after removing the drivers.

3. I cancelled the Windows XP wizard that wanted to search for and
install video drivers for my "new found hardware".

4. I deleted the nVidia folder in the root of my C: drive.

5. I checked for an nVidia folder in my Program Files folder and there
was none (I would have deleted it if it was there).

6. I searched the registry (using regedit) for "nvidia" and deleted all
entries I found.

7. I disabled my Norton Antivirus autoprotect in the system tray.

8. I rebooted again (probably not necessary, but I wanted to be
absolutely sure I had no old driver remnants).

9. I downloaded the latest Forceware drivers from nVidia's web site
(currently version 66.93 dated Nov. 9, 2004).

10. Ran the driver file - it extracted the files to the default
location on my C: drive and it started the setup which installed the
drivers. It asked for a restart, so I let it restart my system.

11. My system rebooted to an 800x600 screen, so I changed it to my
normal 1280 x 1024 x 32.

12. I ran the game's 3D Setup and then the game itself, trying both D3D
and OpenGL, different resolutions, windowed and non - IT STILL DIDN'T
WORK. I noted that the driver settings were all left at the default.

13. I decided to start changing some settings one at a time to see if I
could get lucky. The first thing I did was turn on "write combining"
(found on the "Troubleshoot" tab of the Advanced Display Settings.
Specifically, I right clicked the desktop, chose Properties, clicked
the Settings tab, clicked the Advanced button, then clicked the
Troubleshoot tab. My write combining was unchecked so I checked it,
then rebooted as it asked for.

14. Ran the game again - STILL DIDN'T WORK. I noted that the settings
in the driver were still at default settings. Default settings for my
system (presumably because I have a single monitor) meant that the
nView Desktop Manager was Disabled. It's my understanding that the
nView Desktop Manager is used if you have more than one monitor (maybe
I'm wrong).

15. I started playing around with some of the basic AA and AF settings
in the driver. I tried "Application Controlled", I tried 4X AA and 8X
AF in the driver, but none of this worked.

16. I then went into the nView Desktop Manager properties and selected
the Profiles tab, and the default profile was selected, so I clicked on
the Save button and put some checkmarks in some boxes and saved the
profile. Basically, after fooling with that, I ran the game and
noticed that AA and AF was working! When I went back to the driver to
look at the settings, that's when I noticed that I had a bunch of nView
Desktop Manager options available now and the nView Desktop Manager was
Enabled. Now, all the tabs in the nView Desktop Manager Properties
were available too. Before, only the first 2 tabs were available.

17. Now that it worked, I did some more testing and found that when the
AA and AF in the driver was set to "Application Controlled", it didn't
work in the game. However, now all I had to do was make sure AA and AF
were turned on in the driver and it worked like a charm! By the way, I
did NOT change any of the default settings in the new nView Desktop
Properties tabs that had become available.

I concluded the following from the above (really a guess). It seems
that the only important thing out of everything I did, was to enable
the nView Desktop Manager and set the AA and AF level in the driver
(instead of leaving it as "Application Controlled", which is where I
leave it when I play Doom3 and Half-Life 2). I guess the game it to
"old" for Application Controlled to work.

Anyway, I am SO HAPPY that I finally got it working - I am getting back
into a serious Nascar Racing 2003 Season game with friends that will
last for months and I did not want to have to put up with that friggin'
blockiness for much longer. The best Nascar game looks beautiful again
on my new system, with my new 6800 GT video card!

I'm not sure why the nView Desktop Manager must be Enabled for this
game to work, but it seems to be needed. I'm not even sure what all
the multitude of settings are for in the Forceware drivers, but at
least the AA and AF in the game works now.

I hope you guys find this helpful - it was a pain to do the research
online, and to spend the time testing and performing trial and error
testing, but hopefully this info will help more of you guys who were
suffering the same fate I was with the best Nascar Racing game ever!
Best Regards,
SkykingUSA