USB Kubuntu 8.04 - How to boot from 2nd HD?


I have installing Kubuntu 8.04 persistent on my 2G usb stick,
following the tutorial at the url (
.. That was ok. The problem is: I am using a eeepc 701 with windows xp
on the 2nd hard drive (/dev/sdb1). So i can not run the windows from
the menu options (Boot from first Disk). I tried modify the line:
"localboot: 0x80" to other values (0x81,0x90, etc) and did not work.
(actually, i dont know what i am doing) I just dont understand the
mean of this value or how to set the correct value to /dev/sdb1.

Hope you can help me!