it wasn't when it had just turned on and was warming up was it? i made a ridiculous noob mistake the other day, ran my 400 for 2 months without realizing there was a thin layer of celophane on the underside of the hood....tried to remove it once the bulb was on, *#(*$@ MISTAKE, now i have melted plastic all over one side of my bulb, a fire hazard im sure, ive ordered a replacement, as it is ive double the ventilation on the bulb in an effort to prevent any disasters, still smells a little like burning plastic in my garden lol, so close to harvest too what a bummer