As I once made the same in BF2, here's some Troubleshootings for BF2142 (will add more stuff lateron);
BF2142 Punkbuster Packet Loss Kick.
The guys at RiP have written it down here; http://www.rustyinplaces.org/index.php?option=com_content&task=view&id=65&Itemid=2
PunkBuster™ Support for Battlefield 2142
http://www.evenbalance.com/index.php?page=support-bf2142.php
Battlefield 2142 Tweak Guide
http://www.tweakguides.com/BF2142_1.html