[syslinux] grub in the mbr

[max.ebert at titoly.de]

hi,
i ve grub in the mbr of my usb stick and now i am not longer able to use
the syslinux bootmanager. i tried to delete grub from mbr with:
dd if=/dev/null of=/dev/sda bs=512 count=1

but nothing changed grub is still in the mbr hope somebody can help me

thx so long