Thanks for posting in the Slingbox answers forums. I'm sorry to hear you are unable to get video when trying to take advantage of the video-out feature.
Our engineers are currently investigating this issue. I have noticed that a work around is to switch your input on the iPhone to component, then back to composite. Could you try this and confirm if it works for you or not?
Feel free to reply!
The Sling Moderation Team
We bought the Slingbox PRO-HD only for use when we are traveling and want to watch our home system (Verizon whole-house DVR) from the hotel TV, via either a Gen 1 iPad or an iPhone 4S. (We also have a new iPad and an iPhone 5 but neither apparently supports video out via the Lightning connector.) We have used the component cables provided sold by Apple and also have had good luck with those cables made by others.
All worked pretty well (sometimes video wouldn't show up on the hotel TV, only audio, unless we fiddled with it for a while - annoying but it eventurally worked) and then it stopped completely. After working for hours with the hotel's IT staff, and getting a faster WiFi service installed at the hotel and unhooking and rehooking everything on the Slingbox, I called your Tech Support and learned that you knew about this problem.
Why, given that you have everyone's email, wouldn't you simply send an email to everyone with something like "If you are having trouble watching video on your TV through your iPhone or iPad, ....."? There probably are many others out there still struggling with this major problem and not having any idea that you are aware of it and are working on it.
Any idea when this will be fixed? Is there any chance that Sligbox will work for showing videos on hotel TVs via the iPhone 5 or new iPad?
Another issue -- I think that the Slingbox app could use an earier interface for skipping forward and back when watching shows that are on our home DVR. It's so balky and it's easy to hit the wrong button on the remote