My ipad app seems to work intermittently, it works fine when displaying the TV guide, but sometimes it wont connect to my hd box when I want to record or view my planner. This can last for weeks and then all of a sudden it works again? Will work ok for weeks or months and all of a sudden for no apparent reason reverts back to "not able to connect"

Tried all of the usual, turning off box, removing plug from the mains, uninstalling/ reinstalling app. I haven't changed any settings so am at a bit of a loss as to why this happens.

Anyone experiencing the same or able to advise on a possible cause?