Marvel Ultimate Alliance 2 PSP problems?

[Deceleration]

I have had Marvel Ultimate Alliance 2 on the PSP since it came out. However, it lags during fighting times and the sound is off on some characters. Has anyone experienced this? Keep in mind though, I do have the first edition of the PSP. Do I need and upgrade or a new PSP for this to resolve itself? Thanks.

[Vitamin]

I've played and beat this game, and let me go ahead and warn you that this game is chalk full of problems. It's a nice game, but there is lagging and other problems this game has that prevents it from being as good as the first game.

[Deceleration]

Oh well. I blame the fact that they used Savage Entertainment instead of Vicarious Visions to put out the game on the PSP. The first MUA for the PSP was PERFECT with no problems I can think of. I'll just keep on keepin on with it. Or just save up for the Xbox 360 version after I buy the Xbox haha