There is a race condition currently if a speaker clicks "I'm done speaking" and a chair clicks the "Next Speaker" button, and we've lost items in the queue when this happens. One option is to essentially freeze the "Speaking" area in the chair UI to what's currently shown when the chair's mouse is over the area, along with the related entry for the current speaker, That way, if the chair clicks "Next Speaker" at (or near) the same time that the speaker click's "I'm done speaking", you can verify that the topic you intended to advance is still the active topic.