I have been trying for many days now to get ubuntu installed on western digital passport 1 TB USB external hd attached to my MacBook Pro (with intel Duo Core processor). I have installed the latest ubuntu 11.0.4 64-bit (needs to be 64-bit for work) on the external USB hd, and when I reboot rEFIt shows a new penguin icon. So, I selected that, and I see a screen with a penguin in the middle for a while, but then the screen turns black and just has a text error message that says "No bootable device -- insert boot disk and press any key". BTW, I checked that my Duo Core is definitely 64-bit. Also, ubuntu does run off the install CD. Even the wireless works and I can use firefox.

I have been reading lots of forums trying to find a solution. A couple that I have tried:
1) reboot and when in rEFIt, choose the sync option and resync the drives. I did that and now the penguin icon just launches a black screen with a different message about "no valid operating system" or something like that.
2) Another site said the key was to change where boot loader got installed, so during the installation, at some point near the end, there would be an "Advanced" button to click on, and in there I could set grub to install onto sdb, the location/name of my external USB hd. However, in the present version 11.0.4, there is no "Advanced" button on any of the install screens.

Any suggestions would be appreciated. I really wish Mac just used a BIOS instead of this frustrating EFI. Do I need to edit or alter something somewhere? If so, exactly what?