heres my $0.02 as i had to rebuild the bt2 iso after adding the ati module..

after changing the paths from slax to the name of my bt2 directory in make_iso.bat, mkisofs was unable to find isolunux.bin and isolinux.boot

to fix this i edited BT\tools\WIN\config and changed the paths to something that looked like this:

-b "boot/isolinux/isolinux.bin"
-c "boot/isolinux/isolinux.boot"

hope this helps someone.