Credit Card Tax Issue

We are implementing Corporate Credit Cards into our instance (patch level 24C). The transactions which are created within Payables have no tax against the credit card provider invoices (expected, but does have a tax code of standard against the lines). The employee expenses payment requests (within invoices screens) generated show the expected tax, but an automatic reversal line is applied within the accounting for the tax lines. This means nothing is tagged into the relevant accounts to be VAT recoverable. We have tried multiple tax changes to prevent the tax reversal line being included within the