I use SuperDuper! version 2.6.2. It seems that SD ("SDcopy") crashed in the background? I read various posts on this forum about SD "hanging" -- everybody had a unique approach to the issue but the symptoms were the same. That's why I did not start a new thread. I hope it does not confuse future readers.
My set up is a bit old timer for the year 2011 -- I'm using a white iBook dual USB, running Tiger 10.4.11.
I tried the "Erase then copy files" method and also running SD from a partition that's totally bare bones (no fancy stuff going on behind the scenes). Always the same issue.
Also I ran DiskWarrior and DiskUtility and all seems just fine.