Oh thank you!!!! I did think of dust in the mold but I make sure to clean really well with mineral spirits and wipe completely dry....hey, could it be the mineral spirits do you think? Come to think of it, sometimes I run them through the oven and just wipe with a paper towel? Maybe we are on to something!!!!! Gosh I will try one with and one without. I have been racking my brain over what I do different!!!!