Hullo Linda:
I remember reading a story in a paper fanfic slash content which stated that Orac was programmed not do anything that would in anyway harm the federation since the origional aim was to sell him ( yes him inspite of my darling's insitence on "it")to the Federation, and that reprogramming him would not only be time consuming but dangerous to the programmer
Ah, even I, despite my very limited reading, remember that one. Bryn Lantry's Mutiny, in Forbidden Star.