[cwsand]

I don't think it resets your I/O configuration, but you should probably save a copy of your I/O config anyway so you can easily restore it whenever you need to. Also, I think the Pref trashing app allows you to select exactly what you're trashing. Whenever I use it, I mainly just go into Preferences afterwards and restore my settings - not a big deal and doesn't take long. It's not something you should have to do a whole lot.