Hi,
Do not use the back to mount the unit. Mount the unit using the grommets and eyelets (flat part of the eyelet goes under the system). Mount the system so there is a clearance under the unit and the white back is not pressing on anything. You can use 1/4" square rails to do this or 1/4" spacers on the screws. The unit should float in the grommets, do not over tighten the screws. Let me know if you have any other questions.