COD4 punkbuster issue... help

Something is wrong with my PunkBuster and it goes deeper than just manually updating it. I recently got COD4 and have been playing in all public servers just fine. However, a select few passworded servers keep kicking me for a "Failure to communicate with PB" error. I have tried nearly everything. I have reinstalled COD4, I have updated COD4, I have the latest patches, I disabled my firewall, I disabled my anti virus I have NO IDEA what else to do. Any suggestions would be appreciated because I play COD4 a lot and enjoy playing in matches occasionaly, but if I can not stay in a passworded server than I dont know what to do. Also, while im in the server that I get kicked from, I constantly get warnings from PB that the server is running a different version, but everyone else in the server is having no problems at all. They have the same PB as I do. Please help me.

Thanks