I changed the post thumbnail size from square to rectangular.
In ATO/Post Thumbnails I have set: Width 180, Height 120, Crop Yes. The original pictures are with ratio 1:1,625, so I have thicked the "Crop" option.
But in the posts category pages (as home I have a static page) the thumbnail in excerpts is not cropped as I wished. Only for new posts (and newly uploaded pictures) it works, when all the older pictures/posts still show a square size.
How to solve this?