differint amount of songs

I have a Sansa fuze+ 4 gb. I got a 16 gb card. I was wonering why on the display it reads 1995 songs and in memory it reads 2199. What gives? 

It might be counting pocasts or audio books in the higher figure. Do you have any of these, or other audio files located in another folder besides the Music folder? Are all your music files tagged in the same format? That could account for the diffference too.

Additionally, are all those songs on the same audio format? Like all mp3? Some of them could be unreadable by fuze that’s why its showing less.