Sony would hate to see you misuse your PSP

"In what must be a record time, Sony has responded to PSP hacker's latest efforts to subvert the handheld's security and play unsigned software and pirate games.

Just days ago, hackers released an exploit that allowed PSP owners to use a copy of the puzzle game Lumines to downgrade their PSPs to an earlier version of the firmware, which was vulnerable to further hacking and homebrew applications.

Sony has just released PSP firmware version 3.51, which closes the holes in the PSP's security, rendering the exploit useless... for those that update, that it.

You have little incentive too, though, with no added functionality introduced in the update. And none of the currently-released games will require the new update either."

Sony foils hackers with PSP update
Lumines hack equal increased sales