I'm from Ohio and have a 700 PSS that has done the same thing. Do to rain and humidity here a Remington Armorer made the suggestion to get one of these or something like it:
http://www.cabelas.com/gun-safes-rem...difier-3.shtml
It seems to help. Also, unless you are transporting the weapon to the range or woods don't store it in standard (the gray solid stuff ) foam because that stuff holds moisture like crazy.