How to boot Crux from a USB stick?

Hi all, I'm trying to put a modified version of Crux 3.1 on a USB stick and make it bootable. After some struggling with syslinux, I got it booting. But then it spits out some messages of the kind "No media found on...", and the system halts. The file structure on the stick is essentialy the same as on the CD. How does Crux determine on which device the media is? Or what else am I missing? Thanks for any help - Bernd -- http://sudrala.de