Finally I've found (by myself, trying to make a new user session and
observing
how it behaves) THE solution. Maybe it can be useful for other people
who meet
some trouble with compiz volatil parameters. I added compiz-manager
(/usr/bin)
at starting applications and IT WORKS.

Anyway many thanks to all people who tried to help. If I have a solution for
a problem explained here, I'll give it.