Double VAT tax on custom field dropdown

[markus.palsson]

Hi,

My question is similar to the one described in this thred: http://forum.virtuemart.net/index.php?topic=113234.0, but I'm not satisfied with the proposed solution (which is to edit core files).

My setup: VM2 version 2.0.20b, Joomla version 2.5.11.

Let's say I have a product with two size options and two prices, a small size for $100 (including 25% VAT tax) and a large size for $200 (including 25% VAT tax). By the use of custom fields I add $80 (equals $100 with 25% VAT tax) to the large size. When I view the product on the front end I then get a drop down list with $100 + $0 for the small size, and $100 + $120 for the large size (note: $120 = $80 + $80*0.25 + $80*0.25) which is incorrect because it should be $100 + $100, thus the tax is added twice to the base price. But it is only in the dropdown list the price is incorrect - if I add the product to the cart I get the product price $200.

So why is the VAT tax added twice to the variant price in the drop down menu? If I go into configuration>pricing in the backend and untick the checkbox "display variant prices with tax" the result is that the tax is not added at all, which is not what I want.

Is this a bug, or else, what am I doing wrong?