Ordered 2 books off 2 UK Amazon sellers last week via my visa debit card. Checked my Natwest account today and each order has had a £1.25 bank charge placed on it.
Looked on the net and found this: http://bluematter.blogspot.com/2010/01/visa-debit-125-charge-for-amazon-and.html
and this: http://www.89pies.com/2010/01/natwest-charging-for-some-amazon-uk-transactions/
Both very recent blogs about it so it's a very new practice I think (I wasn't charged on my last order which was around a week previously, still well within January 2010 though).
Haven't got to the bottom of this yet. I've so far rung Amazon who told me that Halifax, who they bank with, will be emailing me. Going to ring Natwest too and see what's going on.
In the mean time I wanted to warn people that if you don't want to be charged an extra £1.25 per transaction, don't use any Natwest Visa Debit cards on Amazon for the time being. Or possibly any Visa Debit card anywhere online for now! Not sure how widespread this policy is.