Compare it to these two examples:
<set xpath="/lootcontainers/lootcontainer[@id='62']/@size">7,6</set>
<set xpath="/items/item/property[@class='Action0']/property[@name='Magazine_items'][@value='9mmBullet']/@value">9mmBullet,NoAmmo</set>
I'm guessing the /item, either needs to be removed or named @item, but I don't really know this stuff yet.