Activating a Weapon Rack, for the first time, will store the currently equipped weapon on the rack, and it can be retrieved at any time. It is often possible to store Quest-related weapons that are not normally droppable (such as Dravin's Bow) on Weapon Racks.
Sometimes, the weapon will float in mid-air, and will not be attached to the rack.
Forks and knives always levitate perpendicularly to the rack when placed. Occasionally, they will levitate inside of solid objects, making them extremely difficult to retrieve.
The weapon may disappear, making it unable to be retrieved.
Sometimes the improvement, enchantment or unique name on a weapon will disappear.
When the Skull of Corruption is placed on a rack, it will be "standing" next to it, and other weapons can be placed on the rack.
PC 360 Found in Heljarchen Hall Cellar but not limited to. When placing objects upon the five long weapon rack, they must always be placed from the inside out. If a weapon is placed on the outside first, then the immediate space beside will not allow placing anything.
This is fixed by placing objects first in either the center slot or the two inner spaces.HF
PC 360 Sometimes, when placing weapons on the racks, they will appear in the air next to the rack and then fall to the floor.
It is possible to get the weapon on the racks if repeatedly attempted, but not guaranteed. This can also be attempted again at a much later time in the game, and it might be easier for that specific weapon/shield then.