Hi Michael,
The addon domain has to be located in the public_html else it will not be publicly available.
There will not be any visible redirection that takes place and all pages browsed on the addon domain will show as the addon domain's.
Well that's certainly a relief to hear, i'm a little confused, if i've done something wrong though, i have two domains as follows:
telivo host 1 - if i type
http://blahblah.co.uk it works, if i add www. it doesn't...
godaddy host the other - it's been several hours and neither method above work.
i changed the nameservers in both to NS7A.PRIVATESYSTEMS.NET & NS7B.PRIVATESYSTEMS.NET but it's taking a long time to come through - the last time i did this with a free host it took no more than an hour for everything to be working fine so i'm reluctant to think it's the domain hosts which aren't working - are there any settings in cpanel i need to change?
Thanks for your time Dan, you've been a big help

Michael