I know based on the way that Zaaptv works they do run into issues with channel down time... seems like each week its a different set of channels that are affected. Luckily they always bring them back, so just hang in there and they should be working again soon.
This only way to guarantee that these channels will work every minute of everyday is to pay monthly for them. With companies like Dish and Directv charging about $40 a month for their few Arabic channels, I'll take the Zaaptv over that any day.