^^yep, EA screwed PS3 over in that regards.
This game is sick, career mode is hella deep and challenging. I actually lost my first pro fight, the computer AI is actually smart and they know how to box or fight inside, etc and they will switch it up on you (like change their style as fight goes on).
So in online I guess the cheat is just throw a million jabs and straights. I guess that works against some people but all you need to do is bob & weave a few times, follow with a hook and you'll score a flash knock down or stun them. These are the easiest guys to beat, haha. I'm undefeated so far online, the first 3 people I fought used this so called cheat. I bet people will stop doing it as time progresses because if you know how to counter and bob & weave it's simple to KO them.
As of now (7-1 in career mode and a handful of online fights), best boxing game to date.