Battlefield: Bad Company 2 In-game Screen lag, help!?

Recently, a friend gifted BF:BC2 to me via Steam and I installed it. The download went fine, and so did the installation.

However, when I tried playing campaign, I noticed extreme screen lag (choppy motions, very low FPS) and found it impossible to play. But when I tired multiplayer, it worked fine (with some lag, but definitely playable). Is this a problem with my graphics card? I play MW2 just fine at 600x480.... :/



Specs:

Macbook Pro 13", with windows installed through bootcamp

OS: Windows XP Professional (5.1, Build 2600)

Processor: Intel(R) Core 2 Duo CPU P7550 @2.26GHz

Memory: 1766MB RAM

Display: NVIDIA GeForce 9400M 512MB



I did run it at low quality and the lowest resolution - 1024x1000. Help?Battlefield: Bad Company 2 In-game Screen lag, help!?
Not sure what the problem might be. Tried turning off some effects? 1024x1000 is pretty big resolution compared to 640x480... It could be your processor/RAM.Battlefield: Bad Company 2 In-game Screen lag, help!?
Its your cpu and video card. The game is very dependent on cpu so I recommend on upgrading it or overclocking it however, since it is a laptop, I don't think you can upgrade or overclock so buy a new computer. I have the Gateway P-7805u and it is a good gaming laptop for about $1000 and it can run Bad company 2 smoothly.