Also with the 'old' one.
On my site I installed and use the Simple RSS Feed-widget to show some stuff, but unfortunately the feed-entries show up with a very large font. If I use the Twenty-Eleven-theme it looks like the way I would like, but with Atahualpa not.
For an example see http://blog.dickpluim.com and on the left site at the bottom you can see what I mean.

Another thing: everytime I update the theme I have to copy the pictures from the header back as they always get overwritten (when updating from within WP).

Thanx in advance.

this is where you use a tool like the FireBug Extension in irefox to examine the lelment and see what CSS is being applied. Then you can change that css to what you want to use.

It took me two minutes to determine what the issue is so it shouldn't take you long to find it.

I've installed Firebug. Did also some inspecting in IE, and tried adding some stuff to the CSS (through the admin-panel of WP) but without success. After installing Firebug and checking I can't seem to find it unfortunately, so if you would like to give me a clue it would be appreciated. Thanx in advance.

take a look at this

Yep, thanx. I already found out that somewhere the h3-heading showed up, and was trying to remove/modify that in the css but still without success. I'm familiar with a lot of stuff but unfortunately less with css. :-(

So how would I solve this in CSS Stylesheet Editor in the themesettings?

Bit later: SOLVED by modifying wp-simple-rss-feed-reader.php and removing h3 from the line which displays the link.