I have used Ubuntu for several years, and I can not enter password for sudo, and this is when i wanna add a key to public.gpg for itunes10 it dos not work, and the password normal works wite sudo but not in the terminal when i enter:

  sudo wget -q "http:// deb.playonlinux.com/public.gpg" -o-  | sudo apt-get add -

and it says this 'sorry try again', and i just had installed itunes10, and have to add a key whit wget to public.gpg, and i tried to enter in the terminal:

 sudo apt-get update

and the password works fine but not whit using sudo wget, and can some one please help.