Re: Sims 3 AI bugging out.

Try resetting your user files as described in the factory reset described in this post: http://answers.ea.com/t5/The-Sims-3/FAQ-Troubleshooting-Steps/td-p/714/

You won't loose anything. Just make sure to not delete any files  and make a backup.

This will reset all your user files not just remove cc/mods. It's also different from uninstalling unless you already completely got rid of the folder before.