After four days of outage, PlayStation has said that external hackers are responsible - but the prime suspect, Anonymous, has denied all knowledge and says Sony itself is probably to blame.
The company shut down the PlayStation Network last week, hitting more than 70 million gamers worldwide.
In a blog, senior director of corporate communications Patrick Seybold says that the problems were caused by an 'external intrusion', and that the company is planning major work on the system.
"Our efforts to resolve this matter involve re-building our system to further strengthen our network infrastructure," he says. "Though this task is time-consuming, we decided it was worth the time necessary to provide the system with additional security."
Most observers have been pointing the finger at hacker group Anonymous - it has, after all, been swearing vengeance on Sony after it took legal action against George Hotz.
But Anonymous has said it has nothing to do with the attack - a claim that has some credibility, as the attack doesn't seem to have been based on the group's signature Distributed Denial of Service (DDoS) method.
"For once we didn't do it," says the group on its website - going on to claim that Sony could be lying about the cause of the problems.
"While it could be the case that other Anons have acted by themselves, AnonOps was not related to this incident and does not take responsibility for whatever has happened," it says.
"A more likely explanation is that Sony is taking advantage of Anonymous' previous ill-will towards the company to distract users from the fact that the outage is actually an internal problem with the company's servers."