Hello, My cart seems to be miscalculating some VAT calculations by 1 pence, but only on some orders!

for example my cart shows:

sub-total of orders = £86.65
Delivery = £10.00
VAT = 16.92

On a calculator (and VAT calc here) you get:

86.65+10.00 x 0.175 = 16.91375
The 3rd decimal place of 3 should round the result down to 16.91.


Strangely zencart seems to round other orders up and down correctly!?

Any ideas? i have set decimal places to 2 and vat sort order to 0.

Thanks

Guy