Please note this isn't a tax rounding issue - it's functionality not working as intended.
I've just installed 1.8 to start developing a new site and am setting it up for use in Australia. Here, GST (tax) must be visible and included in the advertised price throughout the entire process, but a subtotal is needed showing tax amount (10%).
I also input the price of the goods as including tax. E.g: A product has it's price field entered at $100. This is $100 including Tax. Therefore the catalog / checkout prices must be $100, and the tax calculation breakdown must be
Subtotal $90.91 Tax $9.09 Total = $100
(Note: subtotal isn't required, only tax and total).
My tax settings are as follows.
Tax Class for Shipping : Shipping
Tax Calculation Method Based On : Unit Price
Tax Calculation Based On : Shipping Address
Catalog Prices : Including Tax
Shipping Prices : Including Tax
Apply Customer Tax : Before Discount
Apply Discount On Prices : Including Tax
Apply Tax On : Custom Price If Available
Default Tax Destination Calculation
Default Country : Australia
Default State : *
Default Post Code : *
Price Display Settings
Display Product Prices In Catalog : Including Tax
Display Shipping Prices : Including Tax
Shopping Cart Display Settings
Display Prices : Including Tax
Display Subtotal : Including Tax
Display Shipping Amount : Including Tax
Include Tax In Grand Total : Yes
Display Full Tax Summary : No
Display Zero Tax Subtotal : No
No matter what arrangement I have them, it will either display the prices as if they have been entered not including tax. i.e. the example prices will display as $110 in catalog and cart. Or they will display correctly, but then tax will be added onto that total and it will still come out at $110.
It's like magento is not recognising the setting Catalog Prices : Including Tax which is defined as "Whether catalog prices entered by admin include tax."
Am I doing something wrong or is this a bug?