customizers -- would you be willing to add some "shoutbox testing code". It would capture information such as
* Record of the "send shout" request, and the URL used.
* The contents of the sent document.
* Record of the request for the refresh document, including the URL
* The contents of the received document
After that, it would be a matter of chasing down the processing of the documents.
If you can confirm that "send shout" is working OK, this comes down to then analyzing the processing of the refresh step.
So, either it is not always sending the request for the refresh properly, or it is not processing it properly.
Who can do this?