Hi, juanito.
If you have not saved your documents to permanent storage they will be lost.
I've been saving them to a folder I created in the tce directory. Perhaps I shouldn't do that, but it works. (Maybe it messes up some config files, but so far everything seems okay.)
As a safety measure, you could copy the mydata* files to permanent storage and delete them from their current location.
I can see saving a copy to another disk outside core as a safe backup, but why would I want to delete them from core?
For the purposes of getting things sorted out, it would be better to choose the backup choice "none".
You may be right about that, but I just went with whatever the shutdown dialogue gave me as a default. I figured it knew best. Now what can I do? I've already done one "Safe" backup and one "Backup" backup. <grin>
This is becoming like a Chinese puzzle.
For the purposes of clarity, I suppose I could, as you say, delete the mydata.gz file again and shut down with "None" in the shutdown dialogue. I just don't really want to lose the extensions I've downloaded.
The alternative is re-installing from scratch. But it seems like giving up.
Mike