some plastics breakdown when WD-40 or that bane of techies 409 spray cleaner is used try olive oil or other light veggie oil.
I would highly recommend CRC 2-26 for all electrical and outdoor gear it is a silicone base food,plastic safe, spray. If you have a Home Depot nearby look in the Electrical section the stuff is wonder full, use it on my cars engine to clean and prep for the winter to protect from the salt put down for snow.have used it for 20- 30 years.
http://www.google.com/search?q=CRC+2-26&ie=utf-8&oe=utf-8&aq=t&rls=org.mozilla:en-US:official&client=firefox-a