i get lag only on certain maps and i asked people what it was, and they told me it was frame lag... how exactly can i solve this problem? is it my rates? or my pos integrated gfx....

If you have an integrated graphics card, then that's your problem. You can find a Geforce3 for less than $50 that will play NS quite well. Some maps just aren't optimized especially well, so if your card runs kind of borderline, a bad map will send your fps way down.

Try overclocking your CPU.