So you're trying to play them thru LW's media player? Did you check the system volume level? The speaker icon on the far right of the task bar will allow you to adjust this.

Instead of using the playlist, just try launching the songs from the library & see if it still has the same problem.

Have you tried playing the songs in another player?

Check the length of the song(s)! Are they the normal length or do they seem to run for 20 or 30 mins of silence?