Troubleshooting Sims 3 launcher appears but quits unexpectedly

Today I purchased The Sims 3. I installed it successfully on my mac laptop (macbook mac os x 10.5.8). The installation successfully completed, after the sims 3 launcher comes up and I click the play button the application quits. Initially an error message did appear but I don't recall what it says. I uninstalled the sims 3 and reinstalled it and now the same problem occurs but no error messages appears. I also installed the game on "my passport for mac" (an external hard drive) and the game won't work on that either. PLEASE HELP! I purchased the game from Target and cannot be refunded so this game NEEDS to work!

 

I forgot to mention that i did check and I do have the correct video requirements for the game, i have nvidia 9400M. At least I assume that it's correct as it says that it is a supported video card on the cd packaging.