Help with my files

I recently got my fuze working again and I numbered my files correct but for some reason it wont show up in sequential order.  I put 1 song as 15 and 1 song as 16, but the 16 shows up after song 19 and I dont like it that way since 15 and 16 sync in with each other.   Ive edited them through mp3tag and winamp.  Any suggestions? Is this a glitch?

Order is based on the track number tag, so there must be something worng with your tags.