Does your browser support iframes? Did you try to remove the "Announce entries" plugin temporarily?
Did you try to post a message that does not contain any <a> tags?
Regards,
Garvin
# Garvin Hicking (s9y Developer)
# Did I help you? Consider making me happy: http://wishes.garv.in/
# or use my PayPal account "paypal {at} supergarv (dot) de"
# My "other" hobby: http://flickr.garv.in/
Maybe you can try to view the HTML source of the frame where that "XML-RPC..." message appears and look for errorS? Or did you check your Webserver and PHP error logs for problems? Usually I only hear about an error like this if for example PHP sessions are not properly enabled on the server?
Regards,
Garvin
# Garvin Hicking (s9y Developer)
# Did I help you? Consider making me happy: http://wishes.garv.in/
# or use my PayPal account "paypal {at} supergarv (dot) de"
# My "other" hobby: http://flickr.garv.in/