Originally posted by Eastern Shore Charlie The Lens #22123175
the first 22 numbers indicate that it's made by kiron, and those lenses are known for oil on the blades... ideally, you should be able to visually inspect the aperture blades for oil.
you can get more info on kiron lenses at the kiron club on yahoo... there is a guy in canada who will take the lense apart and clean up the blades for $48, perhaps the store will give you credit, since it appears to be defective? they shouldn't be selling it to anyone.
if you are stuck with it, let us know, it is possible to unscrew the chrome k-mount and try to actuate the blades directly, as a troubleshooting measure.