Ipod Classic Headphone Volume Buttons Not Working

I bought an iPod Classic "7" recently and the volume buttons on the headphones are not working, is this just a part of the iPod or do I have an issue? The pause button in the centre of the buttons on the headphones works fine. My other iPod (nano 5) works perfectly well when adjusting the pausing and volume using an earphone control.

I plugged it in and checked whether or not there was an update and it is displaying that it is on the most current version (2.0.1). I have reset it twice.

Thanks for any help