19:29 Oct 22, 2011 

The translation you have is correct, but misspelled. It is γνώθι σαυτόν, one word, that's why you get the wrong translation into English.
If you want to have it in Ancient Greek you should have it either in capital letters or polytonic. Provided you have polytonic fonts.
Perhaps I can help you with the phrase in pdf or jpg so that you can copy it.
Just let me know...

18:33 Oct 22, 2011 

You might get a better response if you re-post the question in "Greek (Ancient)".

Google's not going to be much help: it can hardly cope with Modern Greek, let alone ancient/classical Greek (which pre-dates the internet by a....few years!).