Q: I have an iPhone 3G. I copy books on CD to my iPhone via iTunes but when I am walking it shuffles even though I have saved it on iTunes as a continuous play. I also ensure that I have it on continuous play in the iPhone itself but it still goes into shuffle mode when I am walking. This only happens when I am walking, when I am driving it is fine.

- Diana

A: It appears as if you’re running into a feature on the iPhone that triggers the shuffle mode whenever the iPhone is shaken. This feature was added in the iPhone OS 3.0 update last spring, and uses the accelerometer to trigger shuffle mode whenever the iPhone is shaken. Fortunately, it can be easily disabled under your iPod settings in the Settings app. Simply toggle Shake to Shuffle to OFF.

Even if Shake to Shuffle is enabled, however, it should only be active when music is actually playing on your iPhone and you either remain in the iPod application or have the iPod controls displayed on the lock screen; shaking the iPhone will have no effect on music playback in any other modes, such as when the iPhone is locked without the iPod controls displayed, or when you are in other applications or even simply at the iPhone home screen. Note also that if you’re running iPhone OS 3.1 or later, you should hear a small “tweedle” confirmation sound when the Shake to Shuffle mode is engaged.