Kate and UTF-8

I have set my system to use en_US.UTF-8. As word processor I use "Kate" with "Kedit" as editor. When I save a file either with "save" or with "save as", it is safed with UTF-8 encoding as it should be. If, however, I first safe the file to one destination (as UTF-8) and later safe it to another location with "save as", the system proposes "koi8-r" as encoding. "Kedit" alone behaves the same. Does anyone have an Idea why and how to correct that? Best regards Ulrich Ruess