SD! Stalls Cloning To Ext. Drive Partition

[Mojo]

The Set-up:

20" G5 iMac iSight OS 10.4.5
External Firewire drive, multiple partitions
iMac connected via a "daisy-chain" of two external Firewire drives

I have used the above set-up for quite some time without a problem, but the new variable is the G5 iMac. During set-up of the new iMac I used Apple's Migration Assistant to move everything over from a G4 iBook.

I am attempting to clone the iMac to a partition that previously had a clone of my G3 iBook. For the first clone I had SD! erase and then clone to the partition.

Both attempts to create a clone have ended with me having to stop and then force-quit (two attempts required each time...) SD! I don't get an error message from SD!; it just copies a miniscule number of files and then stops dead. The first time around 84 files had been copied; the second time it was around 300 files. I wait five or ten minutes without any activity showing in the SD! window.

I have been through the forum and FAQ but I don't have an idea how to proceed.