What? It doesn't display any messages when you apply Ultra settings, unless you're referring to a line in the console somewhere....
No, when you change it to Ultra and go to hit Apply it brings up a little message that says "Ultra settings uses 500mb of graphical data so a 512mb card should be used" something along those lines.
In a timedemo (demo1), on Ultra quality/1280*1024/2x AA/Vsync OFF I get around 70 FPS.
Theres no freakin way dude, I've seen people with better machines not even get that. Check out www.pimprig.com
they have a 'doom3 mini challenge' to see who can get the best FPS under different settings...........wait a second, I just realized something.......you said 2x AA........did you use the nvidia control panel to change it to that or something because Ultra settings = 6x AA automatically and the only thing you can change is AF which you didn't put what you have.
The top dude is a guy named CPUKiller with the following hardware:
A64 3400 (slight OC)
Prototype nVidia 6800Ultra running a modified Golden Sample BIOS
1GB Corsair PC3200LLPRO
Abit KV8 Pro rev 1.1 (1.6 BIOS)
and he only got 54FPS on these settings:
4xAA and 8xAF