From what I've read (and unfortunately I can't remember where I read this), Connery was displeased with them for appearing in a Bond knockoff called Operation Kid Brother that starred his brother Neil. Apparently he felt that his brother was being exploited by the Italian production company that made the film, and he was not happy that they were active participants in the movie. Also part of Connery's irritation with Broccoli and Saltzman, among other things, was that he felt that they could have done more to stop the whole thing - although I don't know what, if anything, they could have done. Again, I don't remember where I read this, so you can take it with a grain of salt, but it seems plausible to me - for whatever that's worth.