Missconfiguratioin with subdomains ???

[rethus]

Hi @ all,
on my Plesk 7.5 Reloaded i use subdomains.
But there goes something wrong.

If i create a Subdomain for <my Domain>, it would be createt on /var/www/vhosts/<MyDomain>/subdomains/<MySubdomain>.

But if i want to save my Subdomain with a Password, the Password-Module creates a new Directory on
/var/www/vhosts/<MyDomain>/httpdocs/subdomains/<MySubdomain>.

So i think there is a misstake in configuration that be used by subdomain-creating.
How can i change the config, that subdomains appear under /var/www/vhosts/<MyDomain>/httpdocs/subdomains/<MySubdomain>.