I had the same problem. I tried with NTSC-U and NTSC-J versions and everytime I wanted to create a new account (or log in to an existing one) I got that message.
The solution was fairly simple:
Instead of using the „main“ server (199.195.251.151) I used the backup server (72.229.137.212) in my PS2 network DNS settings and since then I didn't have any problems creating an account or log in to an existing one.
I re-tried several times, the main server doesn't seem to work for me whereas the backup server works like a charm. I'm currently located in Europe, by the way.
ceno
PS: I'm playing Battlefield 3 on the PS3 almost every day since release but all this „experience“ didn't help me one bit at playing Battlefield 2 on the PS2. I am constantly getting my derrière handed to me

PPS: My player name is „cenorexia“ as well.
PPPS: I see, you already figured the above said out by yourself. Sorry for posting all this again.