I don't think you should make too much of it Vince, however, I can understand that you would question the reasoning behind such a dream. Our subconscious minds absorb things that we would not allow to enter our conscious mind. This may have been a thought that somehow decided to stay in your subconscious for a while. Try not to become nervous about it and realize that it is most likely harmless. If it re occurs in the future (and it will if you dwell on it) see a therapist and dig out the reality of the thought and nip it in the bud.
thanks, i'll try to nip it in the bud as you say.:-)