Can not boot external USB HD grub error 18
 

Hi folks,

I've installed a debian on my externale usb harddisk, here is my partition table

There are two Harddisks one with a windows and one with a linux.

Harddisk (hd2) /dev/sdc
#1 ext3 bootable flag = on size=39.0 GB mountpoint=/
#2 swap bootable flag = off size=1.0 GB

with the debian installer i installed grub by typing (hd2). it seems like the harddisk will write something, and the installer completed this step sucessfully.

so i finished the installation, and reboot the machine. then type F8 to get into the Boot Menu and there appears a USB-Harddisk.
moved down to the entry and typed enter.

but there appears the following error:
Loading Grub Stage 1.5 (yeah im not shure, but i think it was 1.5)

Error 18

and no more!

must i make separate partition /boot?

can anybody help?

thanks a lot

greets willigi