I'm finding that closed captions are sometimes delayed and therefore out of sync with narration or video depending on load times. For example, I have a slide where there is a single asynchronous video and some slide narration. The slide narration takes some time to load and the closed captions are running faster than the narration. Same thing for the video captions. Also not always in synch. I think the slide should not start playing until all the multi media is loaded so that captions, audio and video are always in sync.