I am using blogdesk for few blogs and when they were hosted to old hosting servers that time i can pubish posts using blogdesk software but now while setting this msg appears: http://www.yourblog.com/xmlrpc.php file does not exist while i check file exists and has 644 permissions. and this error is for all those blogs which are running under one hosting account (same server)
Im guessing here so ofcourse i may well be wrong lol, as you said the permission is 644 at the moment, could it be that the file is corrupted/not readable/you think its there but its not ? (Maybe replace the xmlrpc.php with a new xmlrpc.php file from the wordPress 2.7.1 installation and see if it works or not ?)
It is not permission error it seems some options host need to enable i read at 43things.com but his trick renaming file not works for wp 2.7.1