Location of file that needs to be looked at.
path: /usr/lib/openacs/packages/acs-subsite/www/admin
file: index.adp, index.tcl
Variable in index.tcl
set main_site_location [util::configured_location -suppress_port=$suppress_port]
set full_acs_admin_url $main_site_location$acs_admin_url
variable $main_site_location appears to use the IP address, not the hostname when configured for more then one OpenACS instance.