How I did it
In the several attempts I tried at first like the software recommended with the internal script:
With each failed attempt to start I shutdown the VM, restore it completely from the backup and tried again, then each attempt have not run over a "dirty failed scenario". I tried always with the stable version; and in different attempts I choose different between reconfigure the database (sometimes yes and sometimes no), the same with reconfigure scripts, and son on.
After non of the attempts worked I tried downloading the tar file again, uncompressing it and running the command:
# php -q update.php
The same result.
I am using Centos 6.3 and KVM.
Thanks in advance Falko. I have been using your guidelines in Howtoforge for several different software and platforms for years.