I'm getting the

'The response to the metaWeblog.newPost method received from the blog server was invalid: Invalid response document returned from XmlRpc server' error message when trying to publish a post from Windows Live Writer. I can open existing posts but can't then publish them.

If I go to: http://www.nationaltropicals.com.au/xmlrpc/index.php (my site0
There is an error that says 'XML error: no element found at line 1, column 0'

I am using Joomla 1.5.18 (legacy mode) I have tried

Entering my domain with/without www in livewriter
Ensuring I am using correct settings
Enable/disabling ftp layer
Checking permissions are all ok
Disabled bookmarking extensions
Not putting any images in the post

I have attached my windows live writer log.

This issue was due to a conflict with the Virtuemart Product Snapshot plugin. I have disabled the vmproductsnapshot plugin and it's all working now.