iPod 16Gb 5th Generation. pausing and skipping.

had it for about a just over a year now, had no problems what so ever with it. then randomly one day, it just skips through the song, thinking it might just be me knocking the pause button on my headphones, but i let it sit in my hand whilst playing, and it just keeps pausing, and skipping through the song. thinking it may just be a glitch, i done a reboot, within the first 20 seconds of the song, it just done the exact same. it's really fustrating, anybody got any tips? 😕 and operating system, Mac OS X (10.6.8) just updated 10 minutes ago.