Magic cloak from White March is lowering Burn DR on Durance's robes

[afaultytoaster]

I found this cloak upstairs in Durgan's Battery

 

It gives +5 DR for Shock and Burn

 

When equipping it on Durance, it also seems to lower the Burn DR of Durance's robes, resulting in an overall penalty to Burn DR

 

Save: http://www.dropbox.com/s/k7jrrzyk4um6z6f/846b78ab096e48aba76bd8104acdab87%2013724566%20DurgansBattery.savegame

 

 

 

 

[afaultytoaster]

I guess it's because the cloak's bonus is higher than the robe's bonus so it's overridden, but the robe then gets an additional 100% modifier on top. Maybe the modifier should be applied before they are compared?