It appears that you have content (pages, posts or widgets) that contain old URL information.
An example of a URL that is correct:
An example of a URL that is incorrect:
The quickest way to fix this problem would be to do a database dump and then run a search and replace program to find all instances of "hutchisonhaines.co.uk.previewdns.com" and replace them with "hutchisonhaines.co.uk".
I took the liberty of downloading the public version of your site:
wget -r http://www.hutchisonhaines.co.uk/
Then I ran a search to find all instances for you.
You can access the list here:
Here are some plugins you can use to do database dumps:
I'm assuming they create the database dump file (it's just a text file) on the server, so you'll need to find out where it puts that file and then download it.
After you download it, perform your search and replace and then upload the new version and tell it to import the database.
I strongly recommend keeping a pristine copy somewhere incase something goes wrong.