i think every tin i have ever read has told me that if i want to not use all the contents at once i should put it in a non-metallic container.
my dad is a chef, and a food maniac [seriously], and i just asked him!!
he said regardless of whether it is going in a fridge or not, you shouldn't keep food in it because when it is packed it isn't exposed to air and has a special form of plastic seal around the edge, but once you have opened the tin, the inside of the tin will begin to react with the air and will start to rust... although it is very slow, it does.
he's most likely right, what with food hygiene courses etc...