Hey Hey--
I have a couple of questions for you and some stuff you to try:
--How long is a "few minutes" into the game? Did you get to play for 5 or 10 minutes? Were you in C-A-S at the time?
--Do you have any mods or CC? Does your game work without them? Try playing a fresh new save if you haven't already. Does the game still crash?
--Check what patch your base game is following these instructions...go to your Sims folder under Documents and open up the text file "Version.tag." (You can open this file with the application "TextEdit" if it asks you to choose one.) What number does it list? If it doesn't start with 1.50..You need to try patching manually. Here is a post where you can find the link to the SuperPatch for Macs: http://forum.thesims3.com/jforum/posts/list/549552.page
Does the game now work after being patched?
--How many EPs/SPs do you have? What kind of computer are you on and how much RAM do you have?