QUOTE
Try this: Set ISO extension to some favorite application & icon. Install UISO. It steals all the extensions commonly associated with image files and icons ala REAL Media. It's a conspiracy. Try changing settings in UISO and see if they stick? Nope. Change icons in explorer to match what you like; same thing... Once UISO is installed it takes over.
It could be some issue on my computer but I'm not about to argue what I experienced with some bonehead tech response telling me to "uninstall/reinstall and toast my bread darker and all will be fine."
Please uncheck 'Associate UltraISO with the .iso file extension' on installation to avoid this kind of problem.