Problem with carrier prices and taxes?

[PrestaShark]

Hi!

Prestashop 1.5.6 after upgrade from 1.5.4.1, which cause some problems like corrupted installation etc., missconfituration, problems with register and much more. Someone just broke whole shop.

After upgrade almost all is fixed but i noticed that

 I make a carrier price of 20 without VAT in BO, and FO shows 40... ??

I make a carrier price of 20 and 23% VAT and FO shows 49,20

I make a carrier price of 10 and 23% VAT and FO shows 36,90

I make a carrier price of 5 and 23% VAT and FO shows 30,75

I make a carrier price of 1 and 23% VAT and FO shows 25,83...

     
OMFG? WTH?

      HELP!

Edited October 23, 2013 by kisweb (see edit history)

[PrestaShark]

SOLVED!!!
Some very clever set up a specific carrier price in all products!!!

So 20 + 20 = 40

So 20 + 20 * 1,23 = 49,20

and so on...

 

OMG!