Problem with order of songs

I just received a new 8310 for Christmas, so I am just learning the ropes here, but... I have downloaded a course (a series of lectures) onto a SD card. My problem is that the phone keeps reordering the "songs" or lessons. I am not shuffling. How can I reoder the songs or lessons to suit my preference? Thanks.

try renaming them lecture1 of 8 lecture 2 of 8 not sure if it would work but couldnt hurt