problem booting usb-creator flash drives.

[Robert Key]

Hi I am using Maverick and made a usb bootable memory flash drive (4Gb 
8Gb 320Gb) using usb-creator-gtk. It works fine and installation ends. 
When I boot from the flash drive or usb hdd I get the error message

SYSLINUX 4.01
  Error No configuration file found.
No Default or UI configuration directive found!
boot: _____

and of course it won't boot from the flash drive. I have tried a 4GB 
verbatim, 8Gb verbatim and a 320Gb seagate freeagent.  I have also tried 
to boot other computers using these flash drives/usb hdd but I get the 
same error. I once had Grub2 on these devices and maybe the Master Boot 
Record has not been cleared or something like that. I did get 
usb-creator to work a  while ago.

Any help would be appreciated, thanks
Robert Key