Your reply was prompt, Russell. However it did not give me any expert advice other than the information I gave to you. If the advice had solved the problem or provided a workaround or if you could have told me that the camera definitely had a problem, then that would have been better.
Also on sending the camera back to Canon, as I live in the UK then information about sending it back or contacting somewhere in the States doesn't really help. That might not be your fault as I logged in on the UK side and the question might have been transferred to you without your knowing the geographical origin of the problem.
I read your answer and tried out the camera again last night at the dance class. The information from the dpreview gave me some sort of answer and the camera did work a little better. Whether that is luck, or I worked it better or the solution in the review was effective I will only find out in time.
I'm thinking of buying the IXUS 265, the latest version whoich is supposed to have IS etc. This might be better value than fixing a cmera that is already three years old.
I've marked your answer as good but not excellent as I had to rummage through the review to find a possible solution.