Battlefield 2 FPS Jump

Everytime i go into an online sever for battlefield 2 my fps will jump from like 85 to 50 or 50 to 25 etc... my fps keeps on changing while i'm playing and it's making my game very laggy and i can't play it good. It's not my internet i have a very good connection, i have a cpu at 3.53 GHz, and an ATI HIS x1900xt video card, and 2 gig of ocz gold series ddr2, dual channel ram.

what should i do to fix this?

 

Hey,

What settings do you have for the game?

Do you have the latest ATI drivers installed?

 

all settings are on high and anti-analising is on 6x, and it should be with a x1900xt. Yes i have all the latest drivers installed.

 

I had the same problem when i played counterstrike source...i figured out that my problem was that my video card was overheating...check to seeif your card is really hot or something...maybe your computer needs a new fan or something