iPod Nano 2G audio started skipping during music playback - what causes this? My 5 year old iPod Nano "2G" 8GB has recently began skipping during song playback.  It sounds like when a CD skips, a kind of digital glitching sound.  But lately it's gotten really bad, where it will skip repeatedly over a whole verse of a song.

I did some research and found that it's actually possible for Flash memory to get fragmented. Does this really apply to my iPod Nano? 

It is significant to mention this skipping just started happening as I've recently filled the iPod full to capacity.

How can I resolve it?  I have a Windows XP computer.  Would I really want to Defragment this iPod like you would with a spinning hard disk?  Would I be safe to simply Cut &amp; Paste everything off the iPod's drive letter in Windows Explorer?  (Move it all temporarily to my hard drive, and then restore it?)
I have encountered an issue similar to this on my iPhone, both on the 4S and 3GS. It took an embarrassingly long time to diagnose my headphones as the issue. I have a set of Sennheiser earphones with an inline remote, and if the jack becomes damaged, internal wires can get crossed and can start sending commands to the iPod application. I found that the play button would get hammered repeatedly as a result, and caused playback to stutter.

So, if your earphones have an inline remote and a damaged jack, try changing them. You might find a fix is cheaper than expected.