Nothing worked correctly when I tried starting up from the Tiger backup, so I guess there were preexisting problems that were on that backup.
It's strange, though, because my computer was working fine under Tiger when I did that final Tiger backup. Then I updated to Leopard, and the update went fine, and computer worked fine for a few weeks. I also updated regularly under Leopard (as I said, I wasn't aware of the SD/Leopard compatibility issues). Then a few days ago I couldn't start up (gray screen), and then both backups seemed all screwed up. I guess I can understand why the Leopard backup didn't work, but it's weird that the Tiger one seemed corrupted as well.
Oh well. I ended up having to reinstall Leopard, then install applications one by one, then bring data files back in. Seems okay now.
Hope you get a Leopard version of SD out soon
I appreciate the help trying to sort this out.