I bought my MES 30 digital, model #20070910, in May. I use it several times a week but it's not even a year old. I clean with a sponge, dish soap and warm water. A while back I noticed some discoloring on one of my cooking racks and I called Masterbuilt. At first I thought it was rust but looking closer it appeared that it was a copper colored metal and maybe the original coating had worn away??? Anyways Masterbuilt sent me a free cooking rack to replace it. A few months later I noticed more of my racks doing the same. I called Masterbuilt and since I was no longer under warranty they couldn't replace the racks for free but they sold them to me at 50% off. I now have 9 cooking racks for my MES. Problem is now more of them are starting to discolor. Am I the only unlucky person? Has anyone else had this issue? Is it a major concern for contaminating food?