Finally, here’s a handful of general—although perfectly terrifying—troubles.
If the program “unexpectedly quits,” well, that’s life. It happens. This is Mac OS X, though, so you can generally open the program right back up again and pick up where you left off.
If the flakiness is becoming really severe, try logging out (choose
→ Log Out) and logging back in again.
Installing more memory is by far the best solution to this problem. iPhoto loves RAM like Madonna loves attention.
First, try opening iTunes before opening iPhoto. That way, iPhoto will be sure to “see” the open iTunes library.
If that doesn’t solve the problem, you might have to recreate one of your iTunes preference files, like this:
First, quit all of your iLife programs. Open your Home → Music → iTunes folder. Drag the file called iTunes Music Library.xml file to your desktop.
Now open iTunes and create a new playlist by choosing File → New Playlist. (Doing so triggers iTunes to build a new .xml file, which is what you want.) Quit iTunes.
When you return to iPhoto, your iTunes library should show up just fine.