Update to iOS 4.2 and discover that all of the music on your iPhone has disappeared? Don’t worry, it’s happening to a lot of people and there is a quick fix. (iPhone 4, iPhone 3GS and iPod touch owners have been confirmed to experience the problem and the jury is still out on the iPad.) I’ve got the fix after the break and some interesting patent news about Apple.

Quick fix for missing music on iOS 4.2

1. Plug your iOS device into your PC
2. Play a song on your iOS device through iTunes
3. Sync your iOS device
4. Open your iPod app to restore your music library’s catalog system

That fix it? If not, repeat the steps above but in step 2, play Just to avoid confusion, Apple’s iOS 4.2 update is really 4.2.1 if you check on your iPhone’s info screen. That’s the reason why 4.2 took so long to come out. Apple had to go back and fix some bugs that were discovered. It looks like this one slipped through unfortunately. At least a tethered jailbreak is already out for iOS 4.2 on the iPhone 4 and iPod touch 4. That might not be much comfort if you still can’t get your music library to reappear after trying the fix though.

New Apple patents

The other news I promised was about Apple’s new patents. The company has managed to land industrial design patents for the iPhone 4, the iPad and the iOS graphical user interface (GUI). In case you missed it, Time Magazine just named the iPad the “invention of the year.” I can’t wait to see what the iPad 2 looks like.

However, Apple is a well known patent hog. Think it will use its iOS GUI patent to try to throw some lawsuits Android’s way? Google is already having issues about the Java code in the operating system and is in the middle of a lawsuit with Oracle over it. In fact, Google is now saying in court filings that if anything wrong has been done with Java, it’s not its fault. Instead, it’s passing the blame onto third parties. Don’t ask me how.

Hopefully your iOS 4.2 update went smoothly. If your music disappeared, did the fix work? Anyone have this happen to their iPad yet? Wonder if Apple is about to hit Google with a huge lawsuit over Android? Let me know what you think.