Just in case that somebody is interested:
Perhaps I made a little mistake by saying that the Ubuntu was "freshly installed"; in fact it had been installed since a few hours during which I had installed Matlab. So I eventually discovered (by reinstalling etc etc), that there was some compatibility issue between TV and Matlab (?!?).
What I have observed is that installing Ubuntu - installing TV - testing TV - installing Matlab - testing TV (in this sequence), TV was working immediately before Matlab installation, ad it was dead immediately after.
Even if I was not able to understand where the problem exactly was
, I finally found a workaround: installing the version 5.0.xx of TV (which, from the point of view of Wine compatibility (°) is a "platinum" application&version), the two (TV and Matlab) peacefully live together...
Maybe somebody is able to cast some light...
(°) yes, you know, the TV "Linux" version is a Windows version in bundle with Wine..