I had to register and reply to this; simply for the fact that your update suggests the possibility of using the "Debian way" to install the nvidia drivers. I have an old Optiplex GX-270 desktop case that came with the base to stand it on end. The onboard video is an Intel setup, I've never bother looking it over for the numbers as even on a MS OS it sucks. 
I got the comp for free, and semi-recently picked up a "dead" P4 box that had a nVidia GeForce4 MX 440 low-profile AGP card in it for $5. The "dead" PC only had a faulty master drive, the slave 250GB drive was fine, so was the mainboard, nVidia card, 2 memory sticks (1GB DDR), etc. I must have been a masochist in a previous life because I wanted to use the Dell instead of the beige tower...
Scouting for a decent Linux to run on it finally brought me here to #!, and I really like the setup so far. My only hitch has been the nVidia drivers. I think in the last 3 days I've installed and tried over 20 different methods for getting them to work with no success. So this evening, I looked at everything once more to see if I may have missed something. Rechecked the forums here to see if I missed anything. Rechecked Debian's site to see if I didn't try one of the methods. I came up empty-handed.
Thinking on it a bit more to see if there was some other way got me to thinking about past cards and how they needed to be installed on a Windows box. And that is when I found the solution. REMOVE THE NVIDIA CARD! (Capitalized to show importance.
)
A clean install on the Optiplex without the nVidia card naturally gives you the Intel drivers, etc. Then all I had to do was follow the "Debian Way" until it tells me to restart X. I don't restart X, I shutdown the system. Then pop the nVidia card back in, adjust the BIOS to use the AGP video first, then save and allow the PC to boot up. I have my nVidia drivers without the nouveau setup screwing me over. 
I just felt that this needed to be said as this is a sticky about nVidia drivers. I do apologize if this is not the place to post this.