[horde] Horde Login

[MarkyBoy]

Hello Horde Users,

I have a problem!
I cant login in horde.
Everytime when i try to login, the login screen comes always again.

I look in my horde log, and it looks very good,or?

Aug 14 18:42:33 HORDE [notice] [imp] Login success for xxx. at xxx.com 
[XXX.XXX.XXX.XXX] to {localhost:143} [on line 152 of 
"/home/httpd/vhosts/horde/imp/redirect.php"]


I have a Vhost an a subdomain called this: webmail.XXX.com

My Vhost configuration looks like this:

<VirtualHost \
                        xxx.xxx.xxx.xxx:80 \
                        >
        DocumentRoot /home/httpd/vhosts
Alias /home/httpd/vhosts /home/httpd/vhosts/horde/
        ServerName webmail
        ServerAlias webmail.*

        UseCanonicalName Off
        <Directory /home/httpd/vhosts>
                <IfModule sapi_apache2.c>
                        php_admin_flag engine on
                        php_admin_flag magic_quotes_gpc off
                        php_admin_flag safe_mode off
                        php_admin_value open_basedir none
                        php_admin_value include_path 
"/home/httpd/vhosts/horde:/usr/local/psa/admin/plib:/usr/share/php:/usr/local/psa/admin/javascripts:/usr/local/psa/admin/plib/locales:/usr/local/psa/admin/auto_prepend:."
                </IfModule>

        </Directory>
</VirtualHost>

Can somebody help me?

Thanks

Marky