Thanks for getting back Cyril,
Since writing my post my computer gave up completely. Suddenly my graphics card gave up (grey screen with slim vertical lines), and yes I know my iMac model has this problem world wide and Apple is replacing graphics cards for free, but mine JUST happened to destroy itself as I upgraded. Coincidence? I don't think so... For the few minutes at a time that my computer works before it freezes, it is excruciatingly slow.
I think Steve Jobs was the one they needed in there with his perfectionist whip to see things through. They are fast becoming another Vista kind of programming environment. Lazy, incompetent.
I will await your experiences with great anticipation. Good luck!