Couple small debugs in tax and invoices OSCommerce website

ISSUE one: order total and tax bug My OScommerce site is not calculating the tax properly, and I need someone who knows what they are doing to find out why and fix it. When checking out, the total is not always correct, sometimes the tax is too high and sometimes all the numbers are right but the total is not actually the sum of the numbers. Issue two, perhaps related: Then in the invoice and PDF invoice it seems it is not calculating the tax on the transport also, just on the goods. I also need the pdf invoice to read the final table in a different order : subtotal, transport, tax instead of subtotal, tax, transport. There are 3 separate copies of the site, and we need to fix the bug and copy the fix to the other sites: [login to view URL] [login to view URL] [login to view URL] The site is live, so I need the fix ASAP.