While listening to music on your iPod nano, iPod touch or iPhone, do you ever experience a problem where the songs seem to randomly jump ahead in the middle of a song? That’s probably because the “Shake to Shuffle” is turned on. Shake to Shuffle is active by default in iPhones and iPod nano; I believe it’s also on by default on iPod touch.
Shake to Shuffle allows you to shake a compatible iPhone or iPod and immediately change the currently playing song to a different random song. This is often useful. However, if the iPod or iPhone is jostled (for example, while running, or even driving on a very bumpy road) the device will shuffle to the next song.
For iPod nano, Shake can be disabled in two ways. First, you can set the hold switch on the top of the iPod nano to on. Second, you can turn off the Shake feature by choosing Settings > Playback on iPod nano (4th and 5th generation). For iPod nano (6th generation), from the Home screen, tap Settings > Music and then tap the On/Off switch next to “Shake to Shuffle”.
For iPhone and iPod touch with iOS 4, navigate to Settings > iPod, then turn Shake to Shuffle on or off.