Perhaps the whole system need a total makeover. I bought Linux Format downtown, and fired up a Slax in the RAM. The Slax file manager had mounted the local drives of the system. So by now my data could be saved.
- Format a USB drive for the backup.
- Back up all data in /home/ via rsync
- Install Ubuntu U.U. - KDE version.
- Restore via rsync.
Worked like a charm. It seems that my very old PC just needed a brush up.