The OP has already stated that it's not just Shift 2 that freezes and crashes and it indeed happens with other games. Your theory (because that's all it is and certainly not the "REAL problem") would be credible if Shift 2 was the only game that's freezing and crashing but it's not and games which worked fine before but suddenly start crashing suggest a hardware problem. You should read what the OP is saying before randomly blaming one game, especially since the Shift 2 crashing and freezing problem is greatly over exaggerated, especially on internet forums.
As I have stated, I've sorted 4 PS3's all suffering this problem by simply cleaning the lens. I merely gave the OP my advice based on my experience with this problem, whether he decides to follow that advice is entirely up to him and to be quite honest it's neither here nor there to me if he doesn't. Indeed, if he isn't comfortable disassembling the PS3 himself he could take it to a computer repair shop and ask them to do it for him, I'm sure they wouldn't overcharge for a 20 minute task of cleaning a lens