Do you have a battered heraldic mail, that is beside the khergit lamellar? For me the inventory shows the stats of the next left/right item, if you have 2 or more unsheatable items equipped in the inventory screen or more slots than allowed. Its only a display problem, ingame its working fine and if you remove one of the unsheatable items from your current gear, it shows up correct.
Edit: on a second look at the screen (which is hard to see anything on), it seems your really missing the khergit lamellar.
