Ubuntu from external on thinkpadR51

[Bokonism101]

I got a 1TB external HDD, and compressing and storing files away on it is a pain, so I got the bright idea, "What if I boot Ubuntu 11.04 from my external so there's no need to transfer?"

I found this guide:
http://members.iinet.net.au/~herman546/p24.html

I followed all the steps and successfully installed Ubuntu 11.04 on the XDD.

Then, I reboot, enter BIOS, activate USB HDD as bootable drive, relocate it above internal HDD, reboot again.

10.04 boots from internal HDD.

Edit: XDD is mounted in 10.04 off internal, showing as 1TB Filesystem, containing a Ubuntu Home Folder ***

Reboot, access IBM, F12, USB HDD isn't available.

Is this possible to accomplish?

Thanks