If you have habitual problems with other games, then I'd say it's your ps3. If not, then it's probably just that game. Some games freeze a lot. Look at Fallout 3 GOTY. Some people say that game is completely unplayable. I've only played Mafia 2 on the other system so I can't really relate. I've only had problems on chapter 7.
Can't say that I have experienced this problem.
Like said above, if it is habitual with other games, it may be your system. Otherwise, it sounds like a a problem with the game itself. I wouldn't think it would be a problem returning it if it just came out yesterday and is defect.