I agree with DIY2Much2Do. I just installed my Samsung OTR in IKEA Sektion cabinets this weekend and used 2x4's to bump out the range for door clearance. I used matching filler ripped from a 3"x30" filler piece to cover the bottom of the lower 2x4. With my model microwave there is about an extra 1/4" microwave door clearance with the IKEA doors installed. Hope this helps!
Q