Apple has released iTunes 9.2, a version change that incorporates support for the iPhone 4 and for iBooks 1.1. The iTunes 9.2 coverage being tracked by Techmeme is mostly a press release rehash.

If you are running iTunes, you may already know that every once in a while there's a chance that something will go wrong to the point where you can't listen to your music. Here's a collection of information and links that may help you if you're counting on your iTunes library so that you can run that radio show tonight from your laptop instead of searching frantically through the vinyl hunting for old 45s.

Apple official wisdom

One reason that your music might not play and that your iTunes won't open is that your iTunes library has become corrupt. All of your music files are there, but the index that lets iTunes open them quickly has become damaged. If you follow the technical tips below, you can force iTunes to rebuild this index so that it can see all of your music and all of your playlists.

• iTunes for Mac won't open or unexpectedly quits, Apple TS1852.
• How to re-create your iTunes library and playlists, Apple HT1451.
• How to back up your media in iTunes, Apple HT 1382

Outstanding issues from Apple forums

Some recent people having recent problems with specific cases. The links below are mostly for reference in case the simple, straightforward fix described above doesn't work and you need to descend into the weeds of systems administration.

• Apple forum: Itunes 9.2 Crashes whenever I try to open application. Not resolved yet.
• Apple forum: iTunes crashing. Not resolved yet.
• iTunes Updates Are Crap, Join If You Agree ! (Facebook) Irate users can be unhelpful, and it's not clear that everyone on this group has checked every possible avenue of repair.

Systems repair can be tricky. I always recommend that someone have someone else that they can call on in a pinch for issues, whether it be a friend who was a systems administrator in a former life, or your friend in Arizona or New Jersey who knows too much about this stuff. You want to make those friendships long before they are needed.

Edward Vielmetti is the lead blogger at AnnArbor.com.