Erm... started it with the -S option and got this:
VirtualHost configuration:
212.159.97.10:80 is a NameVirtualHost
default server house166gpa.plus.com (/etc/apache/httpd.conf:1018)
port 80 namevhost house166gpa.plus.com (/etc/apache/httpd.conf:1018)
port 80 namevhost rover.diablog.co.uk (/etc/apache/httpd.conf:1024)
no idea what it means. house166gpa.plus.com is the reverse lookup of the IP that "outsiders" (i.e. anyone not on my side of the router) would see. rover.diablog.co.uk (the server) is an alias for that IP.
Anyway, as you can see, mysql.diablog.co.uk is not there.
I've attached the output from the -S bit to this post...