Frustration with shuffle feature

I have loaded a great number of songs to my Sansa Fuze+ and wish to listen to them in random order as I excercise, but the Fuze+ seems to choose the first half dozen by alphabetical order and play them as a play list.  Is there any way to achieve a truely random shuffle of all songs without play lists? Seems like with a random number function present in most programming languages vit would be fairly easy to achieve.  Am I missing something?