Creatin new account leeds to "page not found"

Hi, we created a fresh empty MM server and are having problems now:

at the very first login we get the signup_email page

..snip..

after adding the account details we get the email verification screen

..snip..

and a mail containing:

MM_login_mail.png699x655 44.3 KB

until now everything is looking fine to me.

But clicking the Email verification link we get

...snip... "Page not found"

we tried a lot of configurations but nothing changes.

Any hints? If you like, you may use that link to see the result.

Regards
walter

btw: had to remove 3 images in my very first post. Spam protection?