UPDATE - So, dealer could find nothing when we brought the unit in last week. They suggested it was either something left over from manufacturing or something had leaked in the freezer we didn't catch. At any rate, since they would not clean, I had to pop up the bottom plate which is fastened by plastic rivets and some kind of glue. Once I cleaned everything I now need to replace the rivets and figure out what kind of glue was on outer edges of bottom plate. Anyone have any ideas on glue or size/type of rivets used on these refrigerators?