Welcome to the Community, I'm sorry for the problems you're experiencing in trying to watch come of the On Demand content.
If this still isn't working for you, are you getting an error message? Is the content you're trying to view HD, SD or both? Lastly, are you able to use any other interactive services or apps? Like Netflix, or catch up / on demand from other channels?
Sorry for all the questions, we want to get to the bottom of this issue.