I'm having what seems to be the same issue with NwA among others.
I've tried
1) Forwarding all ports listed for vanilla BF2 as well as designating my client computer in DMZ while trying to join.
2) Following the instructions BloodyDeed posted on page 2 of this thread, and deleting the pbans.dat file before launching PR
3) Reinstalling PR and BF2 from a clean slate in a fresh directory.
4) Using the PB update tool provided by evenbalance
The disconnection occurs after the client has finished synchronizing with the server, I receive about one second's worth of text, sound effects, and visual data behind the map. After that moment of successful communication between the client and server, the client hangs with the message "There is a problem with your connection." and I'm dropped back to the deployment/server selection screen, with a message box displaying "Your connection to the server has been lost."
Win7 64
8GB DDR2
GTX 460 Drivers updated, DX11
AMD quad (Phenom II I think) at 3.0ghz
The tracert to NwA server 1 didn't return any abnormal pings for the distance. I can successfully connect to the HOG 24/7 Muttrah and Tacticalgamer's server, which are both on the same port of 16567. The other servers I've noted to not be able to connect to is CIA's "Kokan" server, and the 26MEU Manhattan Killhouse
Hope this helps find a solution.
Edit; new observation. PnkBstrB is a squirly service that won't stay running, is it critical?
Edit 2; Got PnkBsterB to stay running by creating a batch file that manually installs the service and runs it, then launches the PR shortcut, and by constantly monitoring both the local services in the mmc and the task manager processes tab. Seems reasonably stable. Did some more poking around and PnkBstrK wasn't in either of the system32 or systemWOW64 drivers folders like the evenbalance site was suggesting. I moved a copy from C:\Users\Loluser\AppData\Local\PunkBuster\BF2\pb into both system32\drivers and systemWOW64\drivers. Neither of these things helped, and the servers are still dropping me a second into the connection. New server that drops the connection added above. I've enabled
PB logging, and will try to generate some info.
Edit 3; I can't get the logs to generate at all on BF2 or PR, but they generate great on BF3, I'm now starting to suspect that PB might not be at the root cause of this problem.