Hey... I heard a rumor and gave it a try:
It seems that there was a major upgrade to punkbuster that occured after BF2 was published. So when you're on a server, you PB may be trying to update thus resulting in a good ping to the server but lag while in game.
I update my punkbuster by downloading THIS FILE and then copy the .exe to <drive>:\Program Files\EA GAMES\Battlefield 2\pb. Then run it. It will connect and download the updates you need and install them.
I connected to an ECG BF2 Ranked server and I was lag free. However, most everyone else was still skipping around the screen... so it'll take a while for everyone to get it.
This may not be the cure, but it looks promising.
(found this on EA's bf2 forum
EAUK_Protagonist
Site Admin
Joined: 09 Feb 2005
Posts: 270
PostPosted: Sat Jun 25, 2005 2:16 am Post subject: Reply with quote
This is another known issue with regards to PunkBuster not auto-updating as it should.
If this problem is widespread we'll post a full set of instructions on how to manually update on Monday. Meanwhile we have fed this information in to the team.