Really slow game, no fps drops?

So this morning I wanted to play Tales Of Symphonia: Dawn Of The New World and everything was fine until the title screen, the sound is very choppy and when I get into the game it slows down like I'm playing at 15 fps or something, all this while mantaining a constant 30 fps lock ( I set the limiter to 30 because then it jumps all the way up to like 120), what could be causing this? It certainly isn't my hardware because I ran this game no problem before, I'm using revision 3.5-1655 x64. Either way I'll leave my specs here too:

Intel i5 3570k 3.4GHz
Nvidia gtx 550 Ti