The Sims 3 problem, please help!

[LivelySoul]

Hi everybody.

I am experiencing a problem with my Sims 3. Now I searched all the relevant information on the net before posting, to make sure my question wasn't answered somewhere else.
My problem is that the game keeps shutting down after only 30 minutes or so depending on what you are doing, for example if you are making a sim it will shut down much faster than if you are just playing, but lets just say 30 minutes on average.
The fan starts racing and the computer gets hot and loud and then it just shuts down, but even before it shuts down, it is reeeally slow.


Now some have had the same problem and it was because of the Time Machine and I can say that my Time Machine is off when playing, actually I haven't even done a back up for a long time.
Some say you have to remove and install it again, and I have done that too.
Some say you have to turn down the graphics settings, and I have done that too, they are all on low.
It's been like this ever since I bought the game and I even thought that maybe something was wrong with the CD so I bought the game again.
Also there isn't any firewall or antivirus enabled so it can't be because of that.

And it can't be my computers fault since it's almost new, it has only been used for about a year and the memory isn't full at all and usually it runs smoothly.

So anyway I hope somebody out there knows a little more about this than I, so if you can please help


Hardware Overview:

Model Name: MacBook Pro
Model Identifier: MacBookPro8,2
Processor Name: Intel Core i7
Processor Speed: 2.2 GHz
Number of Processors: 1
Total Number of Cores: 4
L2 Cache (per Core): 256 KB
L3 Cache: 6 MB
Memory: 4 GB
Boot ROM Version: MBP81.0047.B27
SMC Version (system): 1.69f3