Hi, I'm trying to install backtrack and ubuntu on an external USB hard disk, with grub on the external hard disk. I can partition and install ubuntu with no problems. But I've tried so many things , I just can't seem to get backtrack to boot correctly. I installed backtrack without writing to the MBR, I edited my menu.lst file in ubuntu to boot backtrack, but it's not recognizing the partition that backtrack's installed in, keeps saying -

VFS cannot open root device "sdb3" or unknown-block (0,0)
Kernel panic - not syncing.......etc.

I'm sure that it's sdb3 cos I checked it in fdisk -l. I deleted the partition, recreated the partition and reinstalled backtrack 2, and I'm still getting the same error. But now, it's messing up ubuntu. when I try to load ubuntu, it says it cannot load 'apt-get' and it cannot mount my primary hard disk... Does this have anything to do with the LILO bootloader interfering with GRUB or something?

Just to let you know, my disk is partitioned 5 ways: -

sdb1 - Ubuntu
sdb2 - swap
sdb3 - bactrack
sdb5 - (future linux installation)
sdb6 - fat32 shared files

I just don't know what's going on..., I've tried editing menu.lst in many ways, using chainloader, changing sdb3 to sda3, hda3, etc. in case it was named wrongly... just don't know what's wrong...