10.5.1 - can't boot from clone

[mrpeepers]

SD is a great piece of software...

Let me tell you all what problems I'm having with SD and Leopard.

When I boot up and hold down the OPTION key I see the external drive that SD backed up to, and when I attempt to select it to boot from it, all I see is the gray Apple screen with the circular thingy spinning, and nothing happens.

Also, in Startup Disk, I do NOT see the drive available to boot from.

Question. I am perfectly content continuing to make backups on schedule, even if I can't boot from them for the time being, the question I have is, will this method still work for retrieving data, photos, documents, etc., if my main Mac HD fries? I know I can't restore from it (I think) as a result of the compatibility issues with Leopard, but at the very least, will I be able to get my data from the external drive? I can see it when I explore the drive...