I'll tell what I did, since it is working for me, although it's not that great
you need to register the game/ create account at www.eaworldsport.com, this will create profile for you, so each time you start the game ( if your ps3 connected to internet) you will see your profile name and picture at the lower right corner of the screen.
If you already done this, then maybe you have problem with the DLC( only a guess) of the Game, this mean your ps3 profile address is different form the game region.
I'd this problem with fifa 09, as my game dlc was from uk, and my address is from Middle east.
This year I didn't face this problem, as I bought the game for Qatar.
But Remember, I'm not sure about this DLC issue.
Finally you may log in to www.fifa10.com and ask for support.