Thank you all for your comments, I don't feel so bad now towards SmithMicro. However, digital downloads are supposed to be subject to UK taxes, too, but for some odd reason sometimes one gets charged, sometimes not, even though the total is above the permitted limit. I only mention that it is perhaps better to buy software from Amazon because they've always been very open about charges, and of course there's no need to worry about import tax which is included in the price. I shall write to SmithMicro and inform them of my unexpected costs.