The latest flash plug in, 13, will crash your mini 9 when it attempts to play a flash video. Wait until Adobe sorts it out before you upgrade. They're aware of the problem.
Meanwhile if you already installed it, You can get an uninstall app for adobe's website. Do this:
2. download Flash Player 184.108.40.206 from adobe archives for developers.
3. Install and you should be good.
Or google "flash player 13 crashes 10.6.8"
Edit: You can also uninstall Flash player and download Google Chrome browser. It has some sort of flash player built in. The downside is Chrome isn't a great browser in Snow Leopard.