Mp3 player shows too many songs

My mp3 player has been synced with windows media player 11 and when the mp3 player has been unplugged and refreshed, it showed 3125 songs, but when I plugged it back in and counted the songs, it showed 1895 songs. When I unplug it and turn it on and start playing songs, it says unsupported files and then shows some .alb files in the songns area. I need help with this option.