Its Marsden day tomorrow. Ive spent hours sorting Powerpoint presentations. Ive found that what works on my Mac doesnt always work on my windows pc. a small video clip works on mac and on windows but only if they are saved on 2 different pens. Both systems are power point 2007 but they are not compatible . after last weeks panic when they couldnt load my macbook pen. I decided on a belt and braces action. have a copy on each. But I could end up with a heap of different pens. I will be on tenter hooks now going to our next one.