When you say that you changed the DNS and IPs in the LCN admin panel, did you change the nameservers to ns1.dreamhost.com, ns2.dreamhost.com and ns3.dreamhost.com? Or did you add blank and www A records for theharbourtakeaway.co.uk?
One additional way to figure out if the problem is DNS related or DreamHost related is to add entries to your HOSTS file on you local machine to point to the IP address of your DreamHost server for your domain. If that works then it's just a case of either waiting for DNS to propagate or setting up the proper entries in the LCN control panel.
BTW, the "easiest" thing to do is to set the nameservers like I mentioned above.
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