Can't boot

[tommy]

I updated to 10.5.2 from 10.4.11
Got a new LaCie 500GB d2 external frive connected via Firewire.
Partitioned about 350 for Time Machine and 150 for a clone. Used GUID partition table for my MBP 15".
Set to make clone and went to bed.
This morning the computer had rebooted because open application were not running, but it booted from my internal hard disk. There is no record of any activity in the SuperDuper log but there are files on what was previously an empty partition.
I select restart from the Cloned partition in the startup Volume system preferences, the cloned partition is available as a choice. It restarts but from the internal Hard Disk.
I decide to update my clone and see what happens but the clone is grayed out in the SuperDuper pull down menu.
What now?