I don't know if anyone is still having the PnkBstrB driver failure for PnkBstrK.sys but I was able to resolve my issues. I was getting booted out of BF2142 from every server due to an error involving the .sys file. This is the error message I received:
"RESTRICTION: Service Communication Failure: PnkBstrB.exe driver failure (PnkBstrK.sys) ffao"
and here is what I did to fix the problem:
I found PnkBsterK.sys in the System32\Drivers\ folder and tried to delete it since I noticed it was only 22kb. The file that pbsvc or pbsetup had been installing for PnkBstrK.sys was 136kb, but it was installing to the C:\Users\MyName\AppData\Roaming\ folder which conveniently was hidden but I was able to get to it using the explorer address bar. I was unable to delete the 22kb file in windows even after ending some processes and even stopping the PnkBstrA.exe service. So, I started up in safe mode and replaced the 22kb .sys file with the 136kb .sys file. This solved the problem and I can play Battlefield 2142 with no problems at all now.
Please spread the word as I suspect this can happen to a lot of people using Vista.
Good luck.