Thanks for the input people. This issue had really been spoiling my enjoyment of Kerbal. I will post a picture of my rocket if I can wirk out how.
I do have large fins on the bottom of my rocket but I guess the top is quite bulky with my science stuff, and cabin for tourists, cooling radiators etc.
I am in career mode so trying to earn money and science to take my career forward. I can get into orbit with small rocket but I need larger rocket to have enough fuel left over to get anywhere.
What I don't understand is why a rocket works for some chap in a tutorial but when I build the same rocket, I have this flipping problem.
Thanks again