I will chime in to suggest 'pilot error' myself. Amongst the problems I have encountered with Vista, handling JPEG files with LV is not one of them. Until I see code and example files I will be dubious.
As for PowerPoint, it can certainly spit out JPEG files, it is a terrible way to do it IMO. I would at least use Paint. I would never use PowerPoint, I have had to extract some pictures and the results on a good day are bad.
