is it my monitor fault or the nvidia driver?

i bought Nvidia 8800GTS 512MB 2 days ago. before that im using ATI 1650xt. before i change to the 8800GTS.. i borrowed my friend graphic card nvidia 7300LE 512MB. when i was using ATI 1650xt, i can change my resolution to 800x600,1024x768,1152x864,1280x768,1280x1024......etc.. and max is 1440x900. after switching to nvidia, i can only use 4 resolution which is 800x600,1024x768,1152x864 and 1440x900. is this the driver problem or is it my monitor default setting? im using samsung wide Syncmaster 931BW and max res is 1440x900. i used to play game at 1280x768 now im being force to play at max ress . Please help me to fix this

of course i want to play at max res IF dont get any graphic lag.... some game i can run at smooth at max ress but games like crysis... max ress wont do me any good coz the graphic lag is annoying... is there a way to add in 1280x768 res?

The GTS 512MB shouldn't lag at all at that resolution. Unless, you mean that you're stilling using the 7300LE. If that's the case, then yeah, just follow bob's instructions.

Well, with a processor like that the lower the resolution, the bigger the bottle-neck.

Here is an example of what I mean:

At 1280x768:
Let's say your CPU can process 45 rendered frames per second.
Your GPU can render 75 FPS.
That's 30 FPS that aren't displayed because your CPU can't keep up.

At 1440x900:
Your CPU can still process 45 FPS.
Your GPU may only get 65 FPS here since it's a higher res.
You only lose 20 FPS now.

Basically there is a cap on how many frames can be displayed from the CPU. As long as your GPU can render more frames than can be displayed, just keep upping the resolution, it shouldn't slow you down.