Ok after going through the metal thing, I thought, "hey! Why not start a thread about how to insult someone in a very subtle fashion!"
having been in tech support, I have used this one a few times. I am sorry that you did not take the time to read your manual where it shows how to fix this.
It is kinda like using the PEBKAC or ID10T. Another one is F41L (fail) !
So lets hear em! Maybe there will be good ones I can use on professors that think they know it all!