Hi Steve
First a note about the warning you see. It's not an error, just a warning. That means everything works as it should, the server just encountered "bad" programming and worked aroung it itself.
You can set if the server should show this warnings in the Joomla global configration in the "server" tab. For productive servers the "Error Reporting" should be best set to "none".
Now to the warning itself. It means the function "in_array()" doesn't have an array to search in, where it should have one. Most likely this is caused when you don't have saved the SermonSpeaker settings yet. Go to the SermonSpeaker settings and look for the "Columns" tab. There you probably want to check some of the additional informations which should be shown for the various views. If all is unchecked (which is default), it would only show the title of the sermon.
Did this help?
Btw: I will fix this "bad" coding so it should throw a warning anymore in the next release.