Most of the Bohrok canisters I've had have faded stickers on the back, but the actual sets themselves remain relatively unscathed. All my canisters are in the loft at home, but I think it's just the 2003 canister sets which suffered this. My OG Bohrok don't appear to have suffered too much from this, though the 01 Toa sets get bleached pretty easily too. Not too sure on the smell thing though...