Graphical windows at boot disappeared

[Antonio <antonio montagnani gmail com>]

After latest updated (yesterday), when I boot the machine, I see
shortly the graphical window (I mean the window with the graphical bar
representing the advanement of procedure), then it reverts to text
window (and idle apparently on the line activation of /etc/fstab, but
it continues working), then I get the login screen.
Why????

-- 
Antonio Montagnani
Skype : antoniomontag