I've started playing Bioshock 2 on PS3. I'm not far in, just had my first (second maybe, can't remember) boss battle.

I'm having freezing issues. The game has frozen solid on me twice. The first time was during a loading screen. The other two times have been during big sister battles. The music continues but everthing else just stops. Has this happened to anyone else?

I know that it's not an overheating issue as I've been very careful with the PS3 and while it gets warm, it hasn't gotten hot at all.