Don't use Duncan Hines Cake Mixes even if there's no peanut warning.
My son had an allergic reaction this past week to Duncan Hines Classic White Cake mix. There is not a peanut allergy warning on it. He has been tested for the other allergens listed and he is not allergic to them. I called Duncan Hines. Their cake mix is manufactered by a 3rd party manufacturer. They have in writing that it is made on a dedicated line but the DH rep said it is likely that there are nuts at the plant. She said DH is following the law not having a peanut warning because peanuts are not required to be listed because they are not an ingredient. (May have nuts or Made in a factory that process peanuts is not a required warning.)
Here's my son's alleric reaction story: http://gravityofmotion.blogspot.com/2009/05/cake-disaster.html