image nested in <div> appear to be 10px below the corresponding <div>-box

Dear NG-Readers,

First I want to apologize for crossposting this, but I got no idea
where this topic really belongs to. I have built a html-page with some
CSS. Anything behaves as expected, just the two images inside the
<div> with the class attributes "schraffur-bottom" and
"content-bottom" appear 10px below their corresponding containers. As
the two pics are 10px high in total, I think it has something to do
with the images. Anybody got an idea what I did wrong?

--
kind regards,
tomasio
"describing an issue reveals the way to solve it"