I have noticed that when you have a settings block on frontpage and only have it available to frontpage, if you add a settings block in a course and then change the frontpage block to be site-wide, you end up with 2 settings blocks in the course with no obvious way to remove either apart from to hide one. Blocks in this situation need a delete icon so that they can be removed - in fact I do not quite understand why there is not a delete icon attached this block at all.