Dear Andy,
Can you try the actions below and see if the problem still occurs:
1. Exit out other viewing session (and other big bandwidth eater problem such as BT download or so)
2. On iPad, double-click the button, running program will be listed. Exit out all running programs to make sure iPad has enough resource.
From there can you start a new viewing session and see how it goes?
thanks,
Amy Lam
5ik.TV