Indeed, page faults smell like RAM problem.
2 gb is the minimmum of RAM required for a MAC - here are the system requirements for LN, the last EP before Generations:
link @EA customer support.
I think MACs behave a little bit better towards RAM than PC (or is it Steeve Jobs propaganda working like a charm on me?). I can give you the example of my PC. With 2 gb I had a lot of problems with the game, freezing, lagging, sometimes crashing to desktop. Yet, for a PC with Vista, 2 GB is above the 1.5 required. I've read somewhere that the real minimum of RAM should rather be 2.5 gb. And indeed, since I've upgraded to 4 gb, I hardly have any problem anymore.
To try with a brand new save is a good idea. Old games grow bigger everytime you play them, this means more data has to be loaded (in your RAM) while you play.
Do you have a lot of additional content installed (store items...)? If yes, you might also want to try without any additional content of any kind. The easiest way to do this is to let the game regenerate a new user's 'The Sims 3' folder. Rename your folder where you have your saves and downloaded content to something like 'The Sims3 - back up'. Start the game, a fresh folder will be recreated, containing no content, no saves, and with the options reset to default. Start a new game there and see if you have the same issues.
