Average item levels seem to be wrong

[Alhanelem]

Jobs that can't use any offhand item don't count the offhand slot; but it appears that the item level average always rounds down. e.g. I have full ilvl70 PvP gear on SMN but there is only one ring available so I have an i90 pve ring.
(70*11)+90 / 12 = 71.666666... and it shows my avg item level as 71. Correct when floored. The offhand slot isn't used.

Also any multi-slot items like heavy armor, flanchards, and cowls count as the same item level for every slot they take up. So a body armor that takes up the head slot too counts as two items of that level.

The soul crystal isn't counted even though it has an item level (as they're all 30 and would drag down everyone's averages)