If I'd have to guess I'd say that Vista was getting confused by the conflicting info within the file.
Take a look at the file properties in Windows (I only have XP at hand), the summary page tells me that while it is a 667x1000 image... it is 72dpi horizontally and only 1dpi vertically.
Try resaving the file in another app or verifying the output of the app you are saving it from originally as having that sort of dpi conflict *can* cause issues depending on how the loader of the image handles it.
Aaahh.. I see it now... well found, dahat!
Hmm... Vista tries to respect the dpi values... interesting..