I did a lot of work with my courses customizing both captions and the audio player itself. The CC options aren’t very customizable in Lectora itself, as they are ultimately controlled through CSS.
Here’s a link to the thread with a sample of how I customized the captions. When it comes to customizing, you can use Camtasia to generate SRT files relatively easily. In Camtasia, you can control the font settings for output, but an XML file may be more useful in the long haul.
Eek – That does not bode well for me come November when I upgrade…If I had to take a quick guess, it might be the seamless play and web accessibility combination? What wasn’t working, was it the course as a whole or just the caption modifications?