I know exactly what you are talking about. IMO it's the white insulation, i've seen this on 2 ticking Clouds, and could clearly see the insulation turned brown/dark. I did not have this smell on 2 non ticking Clouds, but the insulation looked different. I honestly miss that smell...it was kind of a burning smell, but with sweet added to it. Wasn't offensive at all, but I was pretty sure it was due to using the higher temps for too long.