Tax not functioning correctly on admin on one machine

[KarZan]

Hi

I have a peculiar problem. Tax is not calculated on one machine but on another it is. It use to work on that machine earlier but suddenly it stopped working. Firstly on product list page (admin/categories.php) it shows prices without tax and also when you open a product the net price does not include vat (=same prices).

I remember having this problem ones before but can not remember how I fixed it. Rebooting browser and windows does not help nor does clearing browser history data.

Also the strange thing is that the prices do include vat on admin home page as they should.

And to be more strange all works on IE on the same machine.

Has anyone ever seen this behaviour? And more importantly does anyone have any suggestions ho to fix this?

From this one could assume there is something with the settings in the browser but I was in the understanding that the price is calculated in the server side (functions_prices.php/function zen_get_products_display_price($products_id)). So I really do not understand this?