You can get the "cups" for the magnets and they will hold better. You could glue those in or even screw them on, some have holes in them for this purpose.

http://www.leevalley.com/images/icon.../99k3800g3.jpg
Rare-Earth Circular Magnets

http://www.leevalley.com/images/icon.../99k3800g4.jpg
Cups, Discs and Washers for Rare-Earth Magnets

http://www.leevalley.com/hardware/pa...urrency=1&SID=

After you have purchased the magnets, do not walk to close to the shelves... :eek:

We put ours in the back of the van and there was this huge crash as they sought out the metal door...... :lol: