Thanks for the reply.
1. Yes, I have tried that with other Macs and it does work in general (see next paragraph). But it is not possible to use such procedure in the login window (no option there to do it). How to force reboot? How to ssh login and reboot? Sorry for my ignorance.
I must say that the lowercase and capitalcase usually work as expected under normal use of the virtual machine, but sometimes (inconsistent behavior) they work in reverse way (lowercase keyboard generates capitalcase and vice versa) and other times as in the login example above, it gets stuck in uppercase independently of the keyboard (physical hardware keyboard) status for lowercase/capitalcase.
2. Thanks for the advice. I did not know that. You said that it is safe to backup the full VMware Fusion disk images manually in the Finder (drag and drop over the backup disk), but could they be backed up also with applications like SuperDuper!?
Thanks again for all your help.