Actually, I made some further tests now and found that my existing version
(3.43-2) also deleted existing completed mirrors when I tried to update them.

However, I upgraded now to version 3.43-4 and the problems has apparently
disappeared. Maybe it was just a bug in version 3.43-2 or my previous
installation had become corrupted.


I still have to check whether it now also correctly changes all extension to
html.

Thomas