Then you don't, theoretically, need forwarding at all. Just have both domains point to the same IP address, and things should work properly.
If you are using virtual hosts in Apache, you'll need to add ServerAliases for the alternate domains:
I think it is something like:
Code:
ServerName the-iblog.com
ServerAlias *.the-iblog.com the-iblog.co.uk *.the-iblog.co.uk
If you are not using virtual hosts, I think it should just work as is...