inconsistent tax calculation for tax-inclusive line items

[Paul_Cechner]

I have an order with several line items with the exact same prices and quantities (these are JPY):
* qty: 2, unit price: 650 (2 * 650 = 1300)
* 10% tax inclusive
* total tax (from shopify API) 119 OR 118 (seemingly randomly)

From what I can tell it should be 0.1 * 1300 / 1.1 = 118

This happens regularly, and there doesn't seem to be any pattern I can see so far, except so far it seems this is only happening on some tax-inclusive orders

We really need to be able to explain how taxes are calculated to our customers quite soon.