Turn your smoker towards the sun. Look into the wood box as it sets in its normal smoking position (may have to back the woodbox slightly). You should be able to see the 2 forward woodbox holes through the tiny space between the woodbox and the housing that holds it. The heating elements curve under the 2 front holes. Are both curves of the elements touching the woodbox?
Also, when I insert my woodbox into the smoker, I have to gently lower the element a 1/4" to allow the woodbox to be inserted. That way, I know the element can't help but touch the woodbox.