Mp3 skipping songs??

When I play a song on my mp3 player (Curtis Mp3 Player), it will play the selected song,then suddenly I find the song has been skipped randomly (without me pressing any button at all) to the middle of the next song!! Is it the button that is the problem? Does it need replacing? I have had the player for approx two years. The buttons have had similar problems before and has worked well after replacement buttons were inserted. What could be the problem? Help!! Thank you.