Hi Martin.
I had the same problem with a site I was working on. When I validated my code, I got the same string of errors you described.
I fixed the problem by adding a style attribute on the image tag. Also it is a good idea to add to the alt="" tag.
Here's a Pastebin of the code I used. I don't recommend copying it onto your site as it leads to a payment screen for my site. Just look at the <img> tag and notice that the width=1 and height=1 have been removed from the end. As has the border="0".
Hope this helps!
Aaron