Tax setting ignored on payment methods with a % fee of transaction?

[GJC Web Design]

Hi ,

just did a simple check with VAT enabled (developing another tax plugin) and it seems the setting for the Tax (e.g. Apply no rule) is ignored if you set a % charge

VAT ->10%
Cart value $100
with tax $110

payment fee 10% of value - in theory $11 ?

cart comes up with $12.22  - hmm - if the tax was wanted to be applied it should be 11 + %10 Vat = 12.10??? (don't quote me on this.. 

if I then choose to apply tax to the payment charge it adds another 10% on this already wrong figure
Tax -> $1.22 - total payment charge -> 13.44 

But as you can see the tax handling setting is ignored

If I apply a FIXED charge  - e.g. $10 then the setting works

VAT ->10%
Cart value $100
with tax $110

payment fee $10 of value

cart total $120  - correct

If I choose to apply the tax in the payment method with a fixed fee this also works correctly

gives payment charge $11.00 - also correct

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