Since the release of Battlefield 2 1.5 Update (http://blog.freedriversite.com/2009/09/06/Battlefield215UpdateAvailableNow.aspx), I have been able to successfully play BF2 on Windows 7 64-Bit Build 7100. After applying the patch, I played the game for about an hour and then got kicked off the server and received the message "Visit www.evenbalance.com to update your security files". I then went to EvenBalance and manually updated my PunkBuster files using PB Setup: http://www.evenbalance.com/index.php?page=pbsetup.php.
Since applying the patch and updating Punkbuster, I have been able to play the game repeatedly with no errors.