Centos – apache on Cent OS opening default page on https

I am new to Apache and SSL and its configuration. I have got VeriSign certificate to secure my site. I have public, private and ca_intermediate cert files. I have configured ssl.conf as below:

 VirtualHost _default_:443>
 DocumentRoot /var/www/mydomain.com/web/
 ServerName mydomain.com:443
 ServerAlias www.mydomain.com 
 # Use separate log files for the SSL virtual host; note that LogLevel
# is not inherited from httpd.conf.
ErrorLog logs/ssl_error_log
TransferLog logs/ssl_access_log
LogLevel warn

#   SSL Engine Switch:
#   Enable/Disable SSL for this virtual host.
SSLEngine on

Problem is that when I access www.mydoamin.com with HTTP it works fine, but when I access using HTTPS it just opens the default Apache page, but with green HTTPS padlock, which means my certificates are installed correctly. How can I get rid of this situation.

EDIT
Output of apachectl -S

-bash-3.2# apachectl -S
[Mon Aug 27 10:20:19 2012] [warn] NameVirtualHost 82.56.29.189:80 has no VirtualHosts
[Mon Aug 27 10:20:19 2012] [warn] NameVirtualHost 82.56.29.189:443 has no VirtualHosts
VirtualHost configuration:
wildcard NameVirtualHosts and _default_ servers:
_default_:8081         localhost.localdomain (/etc/httpd/conf/sites-enabled/000-apps.vhost:10)
*:8080                 is a NameVirtualHost
         default server localhost.localdomain (/etc/httpd/conf/sites-enabled/000-ispconfig.vhost:10)
         port 8080 namevhost localhost.localdomain (/etc/httpd/conf/sites-enabled/000-ispconfig.vhost:10)
*:443                  is a NameVirtualHost
         default server mydomain.com (/etc/httpd/conf.d/ssl.conf:81)
         port 443 namevhost mydomain.com (/etc/httpd/conf.d/ssl.conf:81)
*:80                   is a NameVirtualHost
         default server app.mydomain.com (/etc/httpd/conf/sites-enabled/100-app.mydomain.com.vhost:7)
         port 80 namevhost app.mydomain.com (/etc/httpd/conf/sites-enabled/100-app.mydomain.com.vhost:7)
         port 80 namevhost mydomain.com (/etc/httpd/conf/sites-enabled/100-mydomain.com.vhost:7)
Syntax OK