Syslinux - May 2003 - ISOLINUX d'ont boot when to many file are put on cd

I'm using islonix to build my own 'el torito cd bootable'.

I use mkisofs : "mkisofs -o c:\temp\toto.iso -r -J -V "toto" -v
-no-emul-boot -boot-load-size 4 -boot-info-table -b
isolinux/isolinux.bin -c isolinux/isolinux.boot -sort
src\isolinux\iso.sort  -A "toto" data"

When i put only 1-12 files on data/ the cd boot.

But when i put many more files on data/ the cd boot stops after :
'ISOLINUX 2.00 2002-10-25 Copyrigth (c) 1994-2002 H. Peter Anvin'

Do i do a mkisofs option mistake ?
Or is it a isolinux.bin problem ?