Sims 3 help

so i upgraded to snow leopard yesterday and while i was buying it i thought it would be fun to buy sims 3 as well. i upgraded to snow leopard and everything seemed to be fine. i installed the sims 3 and everything seemed to be running fine, i opened the sims made a sim and everything was good the graphics were kinda ****** and it was a little laggy but i figured that was because i hadn't changed the game resolution to the proper selection yet. game play started and i changed the resolution it looked great but it was still extremely laggy to the point where game play is just annoying and i turned the game off. i went to start the game again and all i can get is a black screen the mouse curser is still there then the mouse freezes and i have to hard restart my mac because its frozen, this is the first time it has ever froze on me. anyone know whats going on with this.

game visual settings are all on low and screen refresh is set to 60 which my monitor is.

i have a macbook about a yearold.
2.4ghz intel core 2 duo processer
2gb 667mhz ddr2 sdram
intel gma x3100 graphics card
total 144mb video ram

all of this seems to fit and exceed the system requirements on the game could the fact that i only have the stock video card mean it's not good enough?

i just don't get why the game wont start at all anymore. i am going to try re-installing it now.