Odd VAT Amount not 17.5%

[ronb]

Hi

This is a strange error - my oscommerce is working out the VAT incorrectly

it is 17.5% - and it calculates it correctly for customers and through out the checkout process , but shows the incorrect figure in the admin/catalogue/products section

 

example

 

I have

 

Tax Class: VAT

Products Price (Net): 34.00

Products Price (Gross): 57.80

 

this should read

 

Tax Class: VAT

Products Price (Net): 34.00

Products Price (Gross): 39.95

 

 

can someone point me to the correct .php file where the vat/ tax working out is made, as its probably a contribution i have installed, but as I dont know where oscommerce works out the prices, i cant check it

 

thanks

ron