This what is the error of pb kicks/bans
Kick code explanation
#101 - Communication Failure
#102 - Communication Failure
#131 - Initialization Failure
#132 - Protocol Error
#141 - Distress (This indicates a problem trying to update to the latest version of PunkBuster - it may indicate a problem reaching one of our Internet-based Master PB Servers which can be caused by firewalls, router problems, etc .)
#111 - Bad Name
#112 - Too Many Bad Names
#113 - Too Many Name Changes
#114 - Protected Name
#121 - Negative Score Too Low
#151 - Extended ASCII Characters
#9001 - CVAR value failed range check
#50000s - Aimbot
#60000s - Wallhack
#70000s - Multihack
#80000s - Gamehack
#90000s - 'Cheat' Video Drivers
#100000s - Speedhack
#110000s - Autofire
#120000s - Game Hook
#130000s - Attempted PunkBuster Hack
Solving Persistent problems
Here is a list of many problems encoutered by users and their solution. ( I'll update this list and i'll try to give you as much solutions as possible to your problems ).
Problems with trying to update punkbuster, just update it manually with the step of this post
Change player name or play on a different server ( server restrictions with names like " noob ", racist names etc... )
Caused by using binds or vstrs so change nicknames. Just don't use it on servers with anti spamming restrictions
Restriction made by the admin against teamkilling, kicks you when your score is too low ( negative score )
[#151][Extended ASCII Characters]
use regular letters, numbers and symbols in the player name or play on a different server
[#9001][CVAR xxxxx ( = X ) Must be equal to Y ]
Bad value to a cvar in your config file (for example cvar r_fullbright (=1) must be equal to 0) Just set the value to the right number
Use of aimbot, don't cheat
Use of Wallhack, don't cheat
Use of Multihack, don't cheat
Use of Gamehack, don't cheat
Use of a Video driver hack, don't cheat
Use of speedhack, don't cheat
Use of Autofire, don't cheat
Use of Game hook, don't cheat
Attempted Punkbuster Hack ( PBHack / Screenshot blocker etc... ), don't cheat
You get kicked with this message error when you're infected by a rootkit, clean your computer with any antivirus/antirootkit software
disallowed program/driver 
This message appears when you're using a disallowed macro with one of the following keyboards : Logitech G11/G15/G19
disallowed program/driver 
This problem happens when you're using a too old version of fraps, remove it or install a new version from FRAPS show fps, record video game movies, screen capture software
PnkBstrB.exe Driver Failure ( rarely happens and disappears )
Can randomly happen if your game isn't installed in the same partition than your windows installation. Just move your game to your partition where windows is installed.
Disallowed program/driver 
caused by "cweoaqw.exe " clean your computer, you're probably infected with a virus or a malware.
PnkBstrB.exe initialization failed
It's a firewall problem, check that your firewall allows pnkbstrA.exe and pnkbstrB.exe.
Disallowed Programs/Drivers 
Disable "Enable Steam Community In-Game" in Steam.
Losing key packets
You can usually get that because of your firewall or your antivirus being too strict. Try to stop them and to launch the game again. On call Of Duty 4 " cl_packetdup 5" or something like that can resolve the problem. Can also be a problem from your connection ( too bad connection, wireless connection packets lost etc... )
programs causing a major risk of kick:
-Ventrilo Chat Overlay
-Team Speak Overlay
-ATI Tray Tools (depends on version)
-Game Accelerator (uninstall, then reboot)
-EVGA Precision tool
-DirectX being out of date CAN cause the problem. Google for dxwebsetup. Get it from Microsoft, run it... it 'might' help.
-ATI Tray Tools is a likely cause as well.
-Older versions of fraps
-Old GFX drivers are another suspect, make sure you are running the latest WHQL drivers for your card.
-Out of date X-Fi soundcard drivers
-Outdated version of Winamp and winamp untrusted plug-ins
Always keep in mind that sometimes, Punkbuster issues disappears like they appears so sometimes, a simple reboot is just enough.