Creation of playlist causes double duplication of tunes in albums

When I drag a playlist from my Windows Media Player to synch with my iPod (classic 160gb) the tunes in the albums get duplicated in the iPod so that each tune is listed twice and plays twice when I play the albums outside of the playlist. What's going on?

via iLounge Forums http://forums.ilounge.com/ipod-classic-legacy-ipods/278129-creation-playlist-causes-double-duplication-tunes-albums.html