If you're having any trouble with you're game then please download these patches. They almost work everytime.

Download patches: thesims2.ea.com/update/index.php

If you're still having trouble with your game then contact the sims2 crew. It's the only way you can fix the problem. Don't try to do it yourself, you don't want to make it worse.

http://thesims2.ea.com/help/index.php?pid=Help

There's all the help you can get.