Why does my iPod skip "So Yesterday" by "Hilary Duff"?

Ok, so I have a 4GB, Silver, 3rd generation iPod Nano. It works perfectly fine, It has around 550 songs and around 60% of memory is being used. So here's the issue. The song "So Yesterday" by "Hilary Duff" plays perfectly fine on my computer but it just skips whenever I try to play it. Also, a few days ago when I added "She Got It" by "2 Pistols" it did the same thing. What does this mean? Why does this happen? Please give me details and tell me what to do about it.