Verified answer

go to http://punkbuster.com/index.php?page=pbsetup.php

download pbsetup (the utility to automatically download the lates PB version)

open it up

select your game

press the button that says something like look for updates

BF2 should then be completely updated, if you still have problems with punkbuster, it may be a problem elsewhere, my dual core processor would not allow me to play BF2 online and i was constanly getting PB errors until i disabled a core for play

Un-install the game. and Re-install.... if the problem still consists then -reinstall the 1.4 patch Fingers crossed it works if the problem conists you could consider over clocking your gfx card (IS NOT ADVISED) but is a consideration you could take in