...based on my hardware. The reason I don't think I should be getting lag is because I have an Asus N80V, 4GB RAM, with an Intel Core 2 Duo CPU P8400 @2.26 GHz 2.27 GHz, it's about 2 years old I think. I'm running Vista. I know, Vista. Oh, also I still have 11GBs free in my hardrive. My suspicion is that the laptop is heating up to the point of lag but not to the point of crashing...
Does it sound like my hardware would do it? Or does it sound more like it's overheating?
You should be playing the game on medium. It should run ok at medium... definately NOT high or ultra. Laptops with standard cooling definately heat up... if you arent running it on a laptop cooler... get one now! When you lay it flat on a desk and play games for extended periods of time, its not getting any airflow.
Also, as a general rule its best for performance to keep about 10% of your harddrive free. so if you have a 300gb, you should probly free up some. Run diskdefragmenter and uninstall things you dont need as always.