Whether it's a car engine or an operating system, anything with several thousand parts can develop the occasional technical hiccup. Mac OS X is far more resilient than its predecessors, but it's still a complex system with the potential for occasional glitches.
It's safe to say that you'll have to do less troubleshooting in Mac OS X than in Mac OS 9 or Windows, especially considering that most freaky little glitches go away if you just try these two steps, one at a time:
Quit and restart the wayward program.
Log out and log back in again.
It's theother problems that'll drive you batty.
All kinds of glitches may befall you, occasionally, in Mac OS X. Your desktop picture doesn't change when you change it in System Preferences. A menulet doesn't open when you click it. A program won't open—it just bounces in the Dock a couple of times and then stops.
When a single program is acting up like this, but quitting and restarting it does no good, try the following steps, in the following sequence.
An amazing number of mysterious glitches arise because thepermissions of either that item or something in your System folder—that is, the complex mesh of interconnected Unix permissions described in Chapter 12—have become muddled.
When something doesn't seem to be working right, therefore, open your Applications→ Utilities folder and open Disk Utility. Proceed as shown in Figure B-1.
This is a really, really great trick ...