Are you capturing at 640X480 wolfie? If you are I'm not sure what to suggest.
What I do is brighten the image up on the laptop screen (it does not matter how you do this), get the best focus possible (so you make out the cassini division) & then go back in & alter the settings to how it should be captured at. If you can't see the Cassini division, it could mean your seeing conditions are terrible.
Don't discount something low tech like a magnifying glass held over the laptop screen to get a bigger image to help you with focus either..
Naturally I am going to have a go at reprocessing your images!
