If it's related to pets, there is a good possibility that this has something to do with the spawning of the wild horses as well. Or maybe they get caught on the map somewhere and it makes life difficult for them.
There is also a possibility that your file is completely bogged down. Does it freeze with a new game? Memories, cars and bad spiral staircases can cause a lot of issues in older games.
I think part of Zelie's problem is also that you're running an older version of the Mac OS. You're running 10.5.?? exactly. The game requires 10.5.7 at least so you should be able to do it but because you have so many extra expansion packs and only 2GB, it's really going to bog down the system.
Macs are notorious for having problems with Pets because of horse spawning and everything like that. Usually if I get a bad pause, I hit the P button on the keyboard and wait. After 5 minutes (yes 5), try to hit the buttons Command + tab. This will work if you play in fullscreen mode. It's basically alt tab. If your computer makes the sound that says "No Way, Nuh uh, Ain't Doing it Sister". It means the game really is frozen and not just processing. To avoid having to hold the button down on the back of the monitor (the way you turn off a iMac), I used to just keep hitting Command + Tab until the computer was smart enough to shut down the game itself. It will then create a report to send off and you can then show that to customer support or us probably and someone might know what it means.
