Hello,
all my thumbs are cropped to square-images. /cache/land-098/XXXXXX/PICT0031_200_w200_h200_thumb.jpg In 1.4.14 there was not so. I don't find options to deactivate the cropping to square. The images are in landscape or portrait and the thumbs should be the same.

Option > Theme > Crop thumbnails if your theme uses default image functions and no custom sizes on the theme itself.

Thanks!
Basic Theme.
there is a checkbox. and checkbox is checked is making squares. the info is missing there.

Checkbox checked does not mean square, it depends on the two values next to it. Square is just default.

Thanks to wibbi for asking this question and to acrylian for answering it! The information in this thread has helped me.