We recently purchased and assembled our IKEA crib, model HENSVIK. The crib itself I find very sturdy - but there is this huge gap between the sides of the mattress and the slats of the frame.

Has anyone else had the same problem and found a solution? All I can think of is to stuff a sturdy piece of foam, or maybe even a heavy plank of wood down either side. (I only thought wood because it would be too heavy for a baby to move, and obviously I would sand and finish the piece of wood - paint it white to match.)

Thanks.