PunkBuster I can connect to a server but can only stay in for a about 30 seconds. It says punkbuster kicked me becasue of no packet flow? what is this and how do I fix it?

That means that you were on a private server and either that person kicked you for too much lag (slow connection between your connection and his), or most often that is what happens automaticly when a server admin sets ping time (lag) limits to bump players who weren't getting a clean connection to the server, and the system says you were kicked by the server admin who set the limit.
Fixes:
Try a different server with players located closer to yourself.
Make sure there are not too many people using heavy downloads or streaming applications at your home or on the same network.

You can try to uninstall and reinstall. Once you reinstall, make sure you update the game.

Punkbuster is a chatting tool, pretty much like raptr if you have heard of it. Or you can asociate it with steam's ingame chat. You don't need punkbuster to play the game. You can use it to speak with your friends during the game.

You may want to update the punkbuster. After that, see if your anti virus or firewall is preventing the program from going online.

Try uninstalling Punkbuster completly, make sure its deleted from program files as well, then try installing it again see if this helps.

When choosing a server try to sort the list by ping rate and go with the lowest ping you can that is offering the map and amount of players you are looking for. If you frequently get disconnected or see connection_error on your screen while playing it could be a problem with your actual internet connection dropping packets. To test that you will need to ping a well known server like google or microsoft and see what ping times you get and if any packets are lost. This can by done by clicking start -> run and typing cmd then pressing ok. In the dos box that pops up type ping -n 20 www.google.com and press enter. Significant packet loss and high ping times could mean your connection is saturated from other downloads/uploads, there is some bad cabling or network hardware somewhere, or your ISP is having some problems. If you are connected to a router or other network equipment and assuming you have a high speed connection try connecting directly to the modem provided to you and see if that helps. If the problem continues you will need to contact your internet provider for additional troubleshooting.

Have you updated "PUNKBUSTER"?
or are you playing single player?
Also, if you play multiplayer, it can be your connection.

update your cod 2 with patches ( see xfire.com)

ad update your punkbuster

more than likely due to a corrupted install . remove the game and re-install it.