Hi Thanks for your help. Here is an extract from httpd.conf. Edmontonracing.ca is the only site that is propagated to the server. Everything was working until I change the servername line (in bold). I chnaged it back but it didn't do anything.
NameVirtualHost 69.57.150.44:80
...
Alias /bandwidth/ /usr/local/bandmin/htdocs/
BytesLog domlogs/plain.rackshack.net-bytes_log
ServerName plain.rackshack.net
DocumentRoot /usr/local/apache/htdocs
#Added by cpanel 8.5.5-RELEASE_60 install
ErrorDocument 400 /400.shtml
ErrorDocument 401 /401.shtml
ErrorDocument 403 /403.shtml
ErrorDocument 404 /404.shtml
ErrorDocument 500 /500.shtml
ScriptAlias /cgi-sys/ /usr/local/cpanel/cgi-sys/
Alias /sys_cpanel/ /usr/local/cpanel/sys_cpanel/
Alias /java-sys/ /usr/local/cpanel/java-sys/
Alias /img-sys/ /usr/local/cpanel/img-sys/
Alias /akopia/ /usr/local/cpanel/3rdparty/interchange/share/akopia/
Alias /neo-images/ /usr/local/cpanel/base/neomail/neo-images/
ScriptAliasMatch ^/cpanel/(.*) /usr/local/cpanel/base/redirect.cgi
ScriptAlias /cpanel /usr/local/cpanel/base/redirect.cgi
ScriptAlias /whm /usr/local/cpanel/base/whmredirect.cgi
ScriptAlias /securewhm /usr/local/cpanel/base/swhmredirect.cgi
ScriptAlias /webmail /usr/local/cpanel/base/wredirect.cgi
ScriptAliasMatch ^/webmail/(.*) /usr/local/cpanel/base/wredirect.cgi
ScriptAliasMatch ^/kpanel/(.*) /usr/local/cpanel/base/redirect.cgi
ScriptAlias /controlpanel /usr/local/cpanel/base/redirect.cgi
ScriptAlias /securecontrolpanel /usr/local/cpanel/base/sredirect.cgi
Alias /mailman/archives/ /usr/local/cpanel/3rdparty/mailman/archives/public/
ScriptAlias /mailman/ /usr/local/cpanel/3rdparty/mailman/cgi-bin/
Alias /pipermail/ /usr/local/cpanel/3rdparty/mailman/archives/public/
Alias /interchange/ /usr/local/cpanel/3rdparty/interchange/share/interchange/
#Added by cpanel 8.5.5-RELEASE_60 install
SetHandler server-status
Order deny,allow
Deny from all
Allow from 127.0.0.1
ExtendedStatus On
ServerAlias www.edmontonracing.ca edmontonracing.ca
ServerAdmin webmaster@edmontonracing.ca
DocumentRoot /home2/edmonton/public_html
BytesLog domlogs/edmontonracing.ca-bytes_log
ServerName www.edmontonracing.ca
User edmonton
Group edmonton
CustomLog domlogs/edmontonracing.ca combined
ScriptAlias /cgi-bin/ /home2/edmonton/public_html/cgi-bin/
....