www.hobbycode.com/serendipity_xmlrpc.php

Googled the error message and discovered this:

http://bugs.php.net/bug.php?id=25670

Status is "won't fix" :/

Does that sound like the issue to you?

Hi all, I recently upgraded from 1.1x to 1.21. In so doing, the XMLRPC interface broke. WLW and Blogdesk are the two that I have tried. Currently using XMLRPC 1.32 The message WLW returns is: The response to the metaWeblog.editPost method received from the weblog server was invalid: Invalid response...