I have used pressure cooker for 3 years. This has never happened before. I received my Presto 01362 6-Quart Stainless Steel Pressure Cooker yesterday. Rice cooked with this cooker looks wierd. It taste normal, but looks a little dark and gray. I cleaned the cooker for a second time, carefully. In order to kill bacteria, I also boiled a whole pot of water with it and hold for 20 minutes. Then I cook rice with it, and got gray rice again!!! Anyone can explain this? Someone had same experience online said this might caused by fake stainless steel, and probably heavy metal from the cooker goes into my rice!! So scary!!! Is that true? What's wrong with this cooker?