We're dealing with a known issue that affects video playback in your SlideDecks, and are working to release a patch that will address it. We anticipate releasing a fix within the next week.
As a result, we're currently experiencing a heavier than normal volume of support requests, so we're taking a little longer than usual to respond. Don't worry, we will get back to everyone, but in the meantime, we really appreciate your patience!
If you're tangling with a different issue, these initial troubleshooting tips might be helpful.