Support for SermonSpeaker 3.x is canceled as it is for Joomla 1.5. I will gladly assist you with minor issues but I will not fix any bugs anymore in this releases.
The fix is to upgrade to SermonSpeaker 4.x, which is better anyway.
As a start I would disable the greybox effect of the ScriptureLink plugin as it breaks the feed (the plugin assigns the javascript the wrong way).
You could also try the fixed plugin from Andrei on our Download page.
Also you maybe want to check the error logs from you webserver or turn logging on in the Joomla settings. It looks like the script terminates early for some reason.
Also you could try to disable all content plugins you have running and see if one of them generates this issue.