using grub from an usb stick to boot ubuntu from a hard drive

[Dragonath]

Hey,

for some time now, since my motherboard would not boot from a SATA drive where my Ubuntu root partition was, I have been using an USB stick with grub installed to boot linux from where my computer would otherwise be unable to. However yesterday as I installed Ubuntu 9.04 on my linux partition and copied the necessary entries from the menu.lst generated by the installer to the menu.lst on my USB stick and adding a root command for grub to use the correct partition I get a "Bad file descriptor" error when trying to boot.
I'm stumped as copying boot entries from one configuration file to another worked in the past - I used this system from 8.04 to 9.04 (I ran kubuntu then), but now as I install the vanilla Ubuntu it stopped working. Could there be a reason grub suddenly can't mount my Ubuntu root partition anymore?
The Ubuntu partition in question is ext3.

Thanks in advance

Edit: if do "root (hd2,0)" and then try to "cat (hd2,0)/etc/fstab" (hd2 being the hard drive hosting the linux partition), then I get an error saying "Error 2: Bad file or directory type". Seems as if grub can't mount the partition I need it to. Is this something to do with device maps?

[Tclarkie]

try this
http://ubuntuforums.org/archive/index.php/t-977673.html

[Dragonath]

Got it fixed due to finding out that my computer IS able to boot from a SATA drive after all. :)

Thanks anyway.