How are you connecting your iPod?
2nd zone audio requires an analog audio input (denon had a receiver that down converted digital to analog for 2nd zones, but not anymore. another subject). A lot of receivers have some sort of dock that you can get for them that have a proprietary connection. (denon dock denon receiver for example). Some receivers have a compatible usb input on them that allow you to plug in your ipod via the ipod cable.