And yet nothing seems to change when I've clicked on the following selections in the Wordpress Dashboard under >Writing Settings>Remote Publishing: Atom Publishing Protocol........................Atom Publishing Protocol Enable the Atom Publishing Protocol. XML-RPC................XML-RPC Enable the WordPress, Movable Type, MetaWeblog and Blogger XML-RPC publishing protocols.
Hi JezLF - the "XML-RPC" one is the important one. This may be obvious but may I ask if you have clicked the "Save Changes" button at the bottom of that WordPress settings page after checking the box?
If it's still not working after checking the box and saving changes then I suspect something else in your WordPress configuration is causing the error. Do you have any plugins installed that could be responsible for the issue?