Changed "Listen 443" to "Listen 1.2.3.4:443" in /etc/apache2/ports.conf
[I'm on Ubuntu 10.04 and ISPconfig 3.0.3]
Code:
<IfModule mod_ssl.c>
# If you add NameVirtualHost *:443 here, you will also have to change
# the VirtualHost statement in /etc/apache2/sites-available/default-ssl
# to <VirtualHost *:443>
# Server Name Indication for SSL named virtual hosts is currently not
# supported by MSIE on Windows XP.
Listen 1.2.3.4:443
</IfModule>
<IfModule mod_gnutls.c>
Listen 1.2.3.4:443
</IfModule>