everything worked like a charm for a month with my ubuntu 13.04 machine until today, when i got an empty desktop,
i have only the wallpaper but no menu bar, no launcher bar

i remember that i have installed skype yesterday wich made a system update by itself .

also i have an nvidia official driver that worked great until now

what i can do to fix this please

i really need your help on this guys.

ps : this is the third time ia have this problem after making a system update

thanks and good day or night