Thanks lads for the responses to and interest in my queries, but unfortunately I still seem to be seeking a solution. I should have mentioned in my first posting that I went through the whole creative process again and burned onto a second disc. This time the picture flashing began immediately the slideshow was run, lasted for a number of slides, then recovered for a few slides, then returned to flashing again. A result worse than the first attempt. I will try again with some new, different brand discs but am not very confident that it will work.