Great shots Andrew. I especially like the Jupiter shot. Brilliant detail and colour for its size. Mind you the saturn is no slouch of a shot either, though there seems to be a little too much red and the red and blue looks like it might need a touch of estimate in the RGBshift box in Registax. Nice and sharp though.
I know what you mean about the can of air. Even following the directions I got a squirk of propellant on the chip cover. Didn't realize it until I tried to take some shots Grrrr. I had to make sure it was fully dry so they wouldn't smear when I tried to remove the spots with a clean cotton wool bud. Stubborn buggers they were too. I can't really be sure, not being a techie guru or anything like that, but my chip appears to have a clear cover over it. At least I hope it has the way I gave it a clean. My images don't seem to have suffered from it. What's the surface of your barlow like?
I'm glad my suggestions re avi size is working out for you.