I've set up two dashboards. They both consist of a single sprint burndown gadget, but for different projects. Displaying either one as a wallboard works fine. When they are both displayed in a wallboard slideshow, the first displays fine, the second displays an empty burndown chart. However many more dashboards I add to the slideshow for different projects, only the first is displayed correctly. Is there some extra configuration I need to get the slideshow to work?