Investigating serious "ban problem" on join

Hi there,
a few weeks ago my problems started: if I wanted to join a server, PunkBuster keeps telling me that I have been banned. Well I thought that this could be because of some problems in communication with the PunkBuster client and server, so I updated PB by hand, disabled the firewall for testing reasons but everything didnt help. Almost 75% of the servers I want to join (Warlord, 64 player map, v1.41, ranked) tell me that I have been banned. But I cant remember being banned ever before (stats say the same: http://bf2s.com/player/43418170/). I am used of getting kicked because of high ping, but this is really terrible.

If I, for example, want to joint on your BF2 Warlord Server (=22nd= SAS Regiment Warlord) PunkBuster pops up and tells me:

"Punkbuster-Fehler. Die Verbindung zu Punkbuster wurde getrennt. Grund: you have been BANNED by Server Admin.".

(in english: Punkbuster Error. Connection to Punkbuster was closed. Reason: you have been BANNED by Server Admin.)

Almost all of my favourite servers dont allow me to play on them anymore :/

Now, to get a new clue of what happened there, I've come here and hope you can tell me why your server keeps me away. Whats in the logs of the server, whats the (real?) reason I can't play anymore? I have never cheated on any server. A year ago, I clocked my RAM to high and PB told me in turn that I would use a hack because the RAM was unstable. But I dont think that this could be the reason that I cant join a lot of servers the last weeks.

So please, help me by telling me why exactly the server doesnt allow me to play.

/edit: I also often get kicked out of my account at the end of a round with a "there was an error reading the server" message... just if this has something to do with my prob. I normally can instant-rejoin such servers after I logged back in.