Hey there everyone.

I'm having a problem which i've been banging my head against for hours now and after an exhaustive search on the forums and via google I can't find anyone who is having the same problem as me (there were a couple of close ones but following advice in those threads didn't help)

As far as I can see I've everything set up fine with all the zones and tax rates etc etc all working as they're meant to. When you stick an item in your cart the correct tax shows up alright and the shipping estimator shows the price of shipping plus the tax as it's meant to.

So then you create an account and go to the checkout. Step 1 where you choose shipping method the shipping still displays with the tax as it should but when you go to step 2 & 3 the shipping suddenly drops to it's pre-tax value. V.strange.

I don't think it's an issue with the zones or tax rates because everything else works out fine. I've tried it signing up as a customer from a bunch of different countries and the tax on shipping still gets dropped from Step 2 onwards.

(tax all works as it's supposed to on products by the way - it's just adding tax to shipping costs that is the problem)

If anyone can help me I'd greatly appreciate it.

the site is traditionalirishgifts.com and it's a 1.3.7 site with the big royal mail addon (plus a couple of others such as easy pop and additional sideboxes which surely shouldn't have anything to do with this problem?!?!)

Thanks in advance fellow zencart worshippers