I have picard set to download CAA images of type 'front', and save them to 'cover(.jpg)'. Ideally, it should download only the frontiest image and save it as cover.jpg. Instead, it downloads all images that are marked with type front, and saves them as 'cover.jpg', 'cover (1).jpg', etc.
This happens with stuff like http://musicbrainz.org/release/bef90838-a09d-4853-ae85-6314d3ab5a4b/cover-art which has 4 images marked with type 'Front', but I only want the first one as an identifying image.
This might require a bit of a UI change; wanting only the frontiest image is a bit different than filtering the wanted images by type.