Track numbers not in order...

I have tried with a number of audio books and still noting.. even tried editing the id3 tags. the psp will not put them in number order..??

I have a copy of the new harry potter book on audio, well the mp3's are named

JK Rowling - 01 - 0101 Dudley Demented
JK Rowling - 02 - 0102 Dudley Demented
JK Rowling - 03 - 0103 Dudley Demented
etc..
etc and they are seperated by disk...

Disk 1 has 64 files. Well .. the id3 tags read

0101 Dudley Demented
0102 Dudley Demented
0103 Dudley Demented.. and then it says
JK Rowling .. on the psp but for some reason the PSP can;t keep them in the right order.. i can;t have them in number order..

0209
0205
0206
0207
0208
0117
etc... no particular order..

it;s getting iritating... any ideas?