I've solved that issue uninstalling via YaST2 all " flash "
modules/software and then visited youtube.com via Firefox. Firefox have
noticed that i need plugins to youtube.com work properly, ive installed
and now all its ok.
Sorry for my "no-technic" language and for my bad english, but i have
less than one week of the world Gnu/Linux openSUSE, and i'm Portuguese
resident at Brazil.