OK, so for anyone who is interested, I've solved it - Heres what happened...
I used to host the site with dreamhost, but due to inactivity they must have removed it from their system... However, not from my server so I could still log into it via ftp. I downloaded the contents then did a re-add of the domain.
A few mins later, it was showing a dreamhost 'Site Coming Soon' page meaning the name had resolved. I'm uploading to the 'new' folder it created and it looks like all is good again - Thanks for the help anyway guys
