Jeppview runs fine under Vista with Java Runtime Environment 5 (JRE 5). I think there are problems running under JRE 6 which is what most new machines come with.
Here is a short clip of Jeppview running under Vista in a VM environment (VMWare Fusion, in this case) on my Mac.
http://www.veoh.com/videos/v1272893hrhbmWWp