Liegt's vielleicht an irgendwelche Antivirensoftware?
Since the new components have been installed, I now get kicked from PunkBuster servers for "handshaking failed" or "Losing Key Packets", how can I fix that?
Some other software programs such as virus scanners, firewalls and Internet security software packages are suspicious of any new services and kernel drivers when they are first released. Some of these will block our new components thereby causing the "Losing Key Packets" kicking. Until these various packages are updated to correctly identify PnkBstrA.exe, PnkBstrB.exe, and PnkBstrK.sys as components of the PunkBuster Anti-Cheat System, players who experience PunkBuster kicks due to these conflicts need to either manually adjust the settings of the other software running on their system or disable the other software while playing on PunkBuster enabled servers. The new PunkBuster components make use of network resources and also frequently update files in the Windows system folders. This activity triggers warnings or blocks by some other security programs, some of which consider all unknown programs as threats or malware. Our new components are simply extensions of the existing PunkBuster system using new services and kernel software drivers, and are each signed with Verisign / Authenticode digital signatures for verifiable authenticity purposes. Most major security packages do not block our new components; users with other software that causes these conflicts should contact the vendor of their security package and request an update to correct this conflict.
http://www.evenbalance.com/index.php?page=pbsvcfaq.php