(Item DB Negate Spells) effect not working

[shrek]

magma amulet don't work.

[The Crazy Animal]

Vitoc please check code for an item's negate spells properties in the item database

In this case it would be item 487

[Winterhawk]

The negate spell ability on items isn't working on any that I have tried so far, (magma amulets don't resist magma heat, swamp boots don't negate swamp poison, gnomish fish helm doesn't resist black water in the moat and may not resist drowning in the icy lake as part of the 3rd good quest)