Problem with UK TAX on Invoices and PayPal

[helpmeplease]

Hi,

 

I hope somebody can help?

 

We've been running a Prestashop Site for months without any problems (or so we thought) and it's just been pointed that our site is generating an incorrect Tax amount on all invoices!

 

Fortunately the billed amount is correct - it's the breakdown that's not correct.

 

We're a UK site, Tax Rate is 20%

 

Here's an example order: 5 x £3.99 = 19.95

 

In the breakdown it reads Total Products (tax excluded) - £16.63 <- this amount is incorrect?

 

Total Price (tax included) £19.95 <- correct

 

Pre-tax total £16.63 Total tax £3.33 = £19.95

 

The tax amount should be £3.99

 

I've no idea why Prestashop is generating these figures?

 

Attached is a snippet of the invoice generated by Prestashop

 

We're using Prestashop v1.4.8 - it's not really an option for us to upgrade to a later version of Prestahop at this stage.

 

Is there anything we can do to disable the breakdown on the invoice?

 

Or has someone manged to find a work-around?

 

It seems a pretty major flaw in the software if there isn't a fix for this.

 

Thanks in advance....

 

Brian