Hi Jason. Admittedly was looking in local, but have now looked at the remote MySQL server and there are only tables I've created in there. I re-uploaded the entire webassist folder just in case but same error message and no extra tables on the remote server.
I did find this thread on a similar problem but it doesn't go as far as giving the solution.
I'm wondering whether it's because I added the attach image button to the editor toolbar sometime after the pages where originally created.