setup-bootable should use UUID in syslinux.cfg
Currently it uses what ever device was used when creating the bootable. Devices like /dev/sd* might have different names on new box.
(from redmine: issue id 735, created on 2011-08-24, closed on 2011-10-28)
To upload designs, you'll need to enable LFS and have an admin enable hashed storage. More information