Please try the following troubleshooting tips:

  1. Adjust the video playback settings within the app: visit the app's "Settings" menu (the small gear icon on the top rightof the nav bar) and enable the "Play Video Over WiFi Only" setting
  2. Disconnect other devices from your network
  3. Clear the Acorn TV app's cache by visiting Settings > Applications > Manage Applications > All > Acorn TV and press "clear cache" 
  4. Delete and then reinstall the Acorn TV app